#49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

L

L, l Lactobacillus; Latin; left; left eye; mering in which sounds made by the length; lethal; light sense; liter. lips are prominent. L- In biochemistry, a symbol used as a labile (la¯Јbı¯l) [L. labi, to slip] Not fixed; prefix to indicate that the carbon atom unsteady; changeable. is symmetrical (or achiral) and that only heat l. Destroyed or changed easily three dissimilar groups attach to it. by heat; unstable. Also called thermo- SEE: D-. labile. L1, L2, etc. first lumbar nerve, second lability (la˘-bı˘lЈı˘-te¯) The state of being un- lumbar nerve, and so forth. stable or changeable. LA left atrium. emotional l. Excessive emotional re- La Symbol for the element lanthanum. activity associated with frequent lab Colloquial for laboratory. changes or swings in emotions and label The attachment of a radioactive mood. marker or other chemical to a biologi- labioalveolar (la¯Љbe¯-o¯-a˘l-ve¯Јo¯-la˘r) [L. la- cally active substance such as a drug or bium, lip, ϩ alveolus, little hollow] body chemical (such as glucose, protein, Pert. to the lips and tooth sockets. or fat). The metabolic fate of the labeled labiocervical (la¯Љbe¯-o¯-se˘rЈvı˘-kl) [Љϩ material may be investigated by detect- cervix, neck] Pert. to the buccal surface ing the presence of the label in various of the lips and the neck of a tooth. body sites or in excretions. The labeling labioclination (la¯Љbe¯-o¯-klı¯-na¯Јshu˘n) [Љϩ material is chosen so that it does not al- Gr. klinein, to slope] In dentistry, de- ter the metabolism or action of the sub- viation of a tooth from the normal ver- stance being investigated. SEE: tracer. tical toward the labial side. labeling SEE: tag, radioactive; tagging. labiodental (la¯Љbe¯-o¯-de˘nЈta˘l) [Љϩdens, la belle indifference (la˘-be˘l-a˘n-dı˘f-e˘- tooth] 1. Concerning the lips and teeth, ro˘nsЈ) [Fr., beautiful indifference] A esp. the labial surface of a tooth. 2. Re- disproportionate degree of indifference ferring to the pronunciation of certain to, or complacency about, symptoms letters that require interaction of the such as paralysis or loss of sensation in teeth and lips. a part of the body. It is characteristic of labiogingival (la¯Љbe¯-o¯-jı˘nЈjı˘-va˘l) [Љϩ conversion disorders. gingiva, gum] Concerning the lips and labia (la¯Јbe¯-a˘) [L.] Plural of labium. gums or referring to the labial and gin- l. majora The two folds of skin and gival surfaces of a tooth. adipose tissue on either side of the labia labioglossolaryngeal (la¯Љbe¯-o¯-glo˘sЉo¯-la˘r- minora and vaginal opening; they form ˘nı Јje¯-a˘l) [ЉϩGr. glossa, tongue, ϩ the lateral borders of the vulva. Their larynx, larynx] Pert. to the lips, tongue, medial surfaces unite anteriorly above and larynx. the clitoris to form the anterior commis- labioglossopharyngeal (la¯Љbe¯-o¯-glo˘sЉo¯- sure; posteriorly they are connected by fa˘r-ı˘nЈje¯-a˘l) [ЉϩЉϩpharynx, a poorly defined posterior commissure. throat] Pert. to the lips, tongue, and They are separated by a cleft, the rima pharynx. pudendi, into which the urethra and va- labiomental (la¯Љbe¯-o˘-me˘nЈta˘l) [Љϩ gina open. In young girls, their medial mentum, chin] Pert. to the lower lip surfaces are in contact with each other, and chin. concealing the labia minora and vesti- labioplasty (la¯Јbe¯-o¯-pla˘sЉte¯) [ЉϩGr. bule. In older women, the labia minora plassein, to form] Cheiloplasty. may protrude between them. labioversion (la¯Љbe¯-o¯-ve˘rЈzhu˘n) [Љϩ l. minora The two thin folds of integ- versio, a turning] The state of being ument that lie between the labia ma- twisted in a labial direction, esp. a jora. They enclose the vestibule. Ante- tooth. riorly each divides into two smaller labium (la¯Јbe¯-u˘m) pl. labia [L.] A lip or folds that unite with similar folds from a structure like one; an edge or fleshy the other side and enclose the clitoris, border. the more anterior one forming the pre- l. majus SEE: Labia majora. puce (preputium clitoridis) of the clitoris l. minus SEE: Labia minora. and the posterior one the frenulum cli- l. uteri The thickened margin of the toridis. In young girls, they are hidden cervix uteri. entirely by the labia majora. labor [L., work] In pregnancy, the pro- labial (la¯Јbe¯-a˘l) [L. labialis] Pert. to the cess that begins with the onset of repet- lips. itive and forceful uterine contractions labialism (la¯Јbe¯-a˘l-ı˘zm) [L. labium, lip, sufficient to cause dilation of the cervix short ϩ Gr. −ismos, state of] A kind of stam- and ends with delivery of the products standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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of conception. SYN: childbirth; parturi- effacement of the cervix. This stage av- tion. SEE: illus. erages 12 hr in primigravidas and 8 hr Traditionally, labor is divided into in multiparas. three stages. The first stage of labor, The identification of this stage is par- progressive cervical dilation and efface- ticularly important to women having ment, is completed when the cervix is their first baby. Its diagnosis is compli- fully dilated, usually 10 cm. This stage cated by the fact that many women ex- is subdivided into the latent phase and perience false labor pains, which may the active phase. begin as early as 3 to 4 weeks before the First stage (stage of dilation): This is onset of true labor. False labor pains are the period from the onset of regular quite irregular, are usually confined to uterine contractions to full dilation and the lower part of the abdomen and

short SEQUENCE OF LABOR AND CHILDBIRTH standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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groin, and do not extend from the back from the uterus. The amount may vary around the abdomen as in true labor. from 100 to 500 ml. False labor pains do not increase in fre- The amount of blood loss will vary quency and duration with time and are with the size of the fetus, but the aver- not made more intense by walking. The age is 200 ml. The probability that blood conclusive distinction is made by deter- loss will exceed 500 ml is increased with mining the effect of the pains on the cer- a large fetus or multiple fetuses, as the vix. False labor pains do not cause ef- placental attachment area on the uter- facement and dilation of the cervix as do ine wall is larger and the uterus is more true labor pains. SEE: Braxton Hicks distended, meaning it does not contract contractions. as well after delivery of the fetus, pla- A reliable sign of impending labor is centa, and membranes. The above show. The appearance of a slight probability is less than 5% if the fetus amount of vaginal blood-tinged mucus weighs 5 lb (2268 g) or less. Other fac- is a good indication that labor will begin tors such as episiotomy or perineal lac- within the next 24 hours. The loss of eration will also affect the amount of more than a few milliliters of blood at blood loss. SEE: birthing chair; Crede´’s this time, however, must be regarded as method for assisting with the expulsion being due to a pathological process. of the placenta. SEE: placenta previa. PATIENT CARE: Often pregnant Second stage (stage of expulsion): This women and their partners or a labor period lasts from complete dilatation of coach who will be with them attend pre- the cervix through the birth of the fetus, natal classes taught by obstetrical averaging 50 min in primigravidas and nurses to prepare the patient and fam- 20 min in multiparas. Labor pains are ily for labor, delivery, and care of the severe, occur at 2- or 3-min intervals, newborn. Such classes include exer- and last from a little less than 1 min to cises; breathing techniques; supportive care measures for labor, delivery, and a little more than 11⁄2 min. Rupture of the membranes (bag of wa- the postpartum period; and neonatal ter) usually occurs during the early part care and feeding techniques. Expectant of this stage, accompanied by a gush of couples (or the pregnant woman and a amniotic fluid from the vagina. The support person) should attend classes muscles of the abdomen contract invol- together. The goals of expectant parent untarily during this portion of labor. education are the birth of a healthy in- The patient directs all her strength to fant and a positive experience for the bearing down during the contractions. woman/couple. Labor and delivery may She may be quite flushed and perspire. take place in a hospital, birthing center, or at home. Hospitals offer care in tra- As labor continues the perineum bulges ditional labor and delivery rooms and, and, in a head presentation, the scalp of increasingly, in birthing rooms that the fetus appears through the vulvar simulate a homelike environment. Pre- opening. With cessation of each contrac- natal records are made available in or- tion, the fetus recedes from its position der to review medical, surgical, and gy- and then advances a little more when necological history; blood type and Rh; another contraction occurs. This contin- and esp. any prenatal problems in the ues until more of the head is visible and pregnancy. If the mother is Rh negative the vulvar ring encircles the head like a and if the Rh status of the fetus is un- crown (therefore often called crowning). known or positive, the nurse will admin- At this time the decision is made con- ister Rh immune globulin to the mother cerning an incision in the perineum (i.e., within 72 hr after delivery. episiotomy) to facilitate delivery. If As part of the admission workup of done, it is most commonly a midline pos- the laboring woman, the nurse assesses terior episiotomy. When the head is vital signs, height and weight, fetal completely removed out of the vagina it heart tone and activity, and labor status falls posteriorly; later the head rotates (i.e., condition of membranes, show, on- as the shoulders turn to come through set time of regular contractions, con- the pelvis. There is usually a gush of traction frequency and duration, and amniotic fluid as the shoulders are de- patient anxiety, pain, or discomfort). livered. Initial laboratory studies are carried Third stage (placental stage): This is out according to protocol. The obstetri- the period following the birth of the fe- cian, resident physician or other house tus through expulsion of the placenta staff, nurse-midwife, lay midwife, or ob- and membranes. As soon as the fetus is stetrical nurse examines the patient, delivered, the remainder of the amniotic depending on the site and policy. The fluid escapes. It will contain a small abdomen is palpated to determine fetal amount of blood. Uterine contractions position and presentation (Leopold’s return, and usually within 8 to 10 min maneuvers), and a sterile vaginal ex- the placenta and membranes are deliv- amination determines cervical dilata- short ered. After this, there is some bleeding tion and effacement, fetal station, and standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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position of the presenting part. The at- and draping); sets up delivery equip- tending nurse or midwife monitors and ment; and supports the father or sup- assesses fetal heart rate and the fre- port person (positioned near the pa- quency and duration of contractions, us- tient’s head), positioning the mirror or ing palpation and a fetoscope or elec- TV monitor to permit viewing of deliv- tronic monitoring. The frequency of ery by the couple. The nurse also notes assessment and repetition of vaginal ex- and documents the time of delivery, de- amination are determined by the pa- termines the infant’s Apgar score, and tient’s labor stage and activity and by provides initial infant care after deliv- fetal response. In the past, admission to ery, including further suctioning of the a labor suite usually included a perineal nasopharynx and oropharynx as neces- shave and enema in preparation for de- sary (initial suctioning is done by the livery, but these procedures have been deliverer before delivering the infant’s largely discontinued and are currently shoulders), drying and warming the in- done only if prescribed for a particular fant (head covering, blanket wrap, or ther- patient. The patient should urinate and mal warmer), application of cord clamp have a bowel movement, if possible. (after the deliverer double-clamps the Bladder distention is to be avoided, but cord and cuts between the clamps), and catheterization is carried out only if all positive identification (footprints of in- other efforts to encourage voiding in a fant and thumb prints or fingerprints of patient with a distended bladder fail. mother, and application of numbered The perineum is cleansed (protecting ankle and wrist band to the infant and the vaginal introitus from entry of wrist band to the mother). Eye prophy- cleansing solutions) and kept as clean laxis for gonorrhea and chlamydia may as possible during labor. Special cleans- be delayed up to 2 hr to facilitate eye ing is performed before vaginal exami- contact and to enhance maternal-infant nation and delivery, as well as after ex- bonding, or may be refused by the par- pulsion of urine or feces. ents, on signing of an informed consent. First stage: The patient may be alert An Apgar score of the infant’s overall and ambulating, depending on mem- condition is obtained at 1 min and 5 min brane status, fetal position, and labor after the birth. The infant in good con- activity. Electrolyte-rich oral liquids dition is placed on the mother’s chest or may be prescribed, or intravenous ther- abdomen for skin to skin contact. This apy initiated. The nurse supports the position enhances bonding and main- patient and her partner or other sup- tains infant warmth. Alternately, the port person and monitors the progress infant is put to the breast, and the of the labor and the response of the fe- woman/couple is encouraged to inspect tus, notifying the obstetrician or mid- and interact with the infant. An infant wife of any abnormal findings. When in distress is hurried to the nursery, membranes rupture spontaneously or usually with the father or support per- are ruptured artificially by the midwife son attending, so that specialized care or obstetrician, the color and volume of can be provided by nursery and neona- the fluid and the presence of meconium tal-nurse specialists, and a pediatrician. staining or unusual odor are noted. To If the infant is critically ill, its birth may distinguish it from a sudden spurt of be attended by a chaplain, and photo- urine having a slightly acid pH, the fluid graphs may be taken to assist the par- may be tested for alkaline pH using ni- ents in dealing with the life, critical trazine paper. The fetal heart rate, an time, and possible death of the infant. indicator of fetal response to the mem- Third stage: The nurse continues to brane’s rupture, is noted. Noninvasive monitor the status of the patient and the pain relief measures are provided, pre- fundus through delivery of the placenta scribed analgesia is administered as re- and membranes (documenting the time), quired by the individual patient, and re- examination of the vagina and uterus for gional anesthetic use is monitored. trauma or retained products, and repair Patient-controlled epidural anesthesia of any laceration or surgical episiotomy. (PCEA) or continuous epidural anesthe- The placenta is examined to ascertain sia is frequently employed, based on pa- that no fragments remain in the uterus. tient satisfaction regarding its timeli- The perineal area is cleansed and the ness and effectiveness, and the patient’s mother is assisted to a comfortable posi- preference for having pain management tion and covered with a warm blanket. under her control. Fourth stage: The nurse continues to Second stage: The patient may deliver observe the patient closely and is alert in any agreed-on position, including li- for hemorrhage or other complications thotomy or modified lithotomy, sitting, through frequent assessment, including or side lying, in a birthing chair, in a monitoring vital signs, palpating the birthing bed, or on a delivery table. The fundus for firmness and position in re- nurse, midwife, or physician continues lation to the umbilicus at intervals (de- to monitor the patient and fetus; pre- termined by agency policy or patient short pares the patient for delivery (cleansing condition), and massaging the fundus standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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gently or administering prescribed oxy- augmented l. Induction of labor. tocic drugs to maintain or assist uterine back l. Labor involving malposition contraction and to limit bleeding. The of the fetal head with the occiput oppos- character (including presence, size, and ing the mother’s sacrum. The laboring number of clots) and volume of vaginal woman experiences severe back pain. discharge or lochia are assessed peri- SEE: occiput posterior, persistent. odically; the perineum is inspected and complicated l. Labor occurring with ice applied as prescribed, and the blad- an accompanying abnormal condition der is inspected, palpated, and per- such as hemorrhage or inertia. cussed for distention. The patient is en- dry l. A colloquial and imprecise term couraged to void, and catheterization is for labor associated with extensive loss performed only if absolutely necessary. of amniotic fluid related to premature The nurse notifies the obstetrician or rupture of membranes. midwife if any problems occur or per- dysfunctional l. Abnormal progress sist. This period also is used for parent- of dilation and/or descent of the pre- infant bonding, because the infant is senting part. usually awake for the first hour or so af- false l. Uterine contractions that oc- ter delivery. The mother can breastfeed cur before the onset of labor (i.e., that do if desired, and the immediate family not result in dilation of the cervix). They couple can inspect the infant. The nurse may resolve spontaneously or continue supports the family’s responses to the until effective contractions occur and la- newborn, as well as to the labor and deliv- bor begins. SEE: labor; Braxton Hicks ery experience. The infant is then taken contractions. to the nursery for initial infant care. hypertonic l. Condition in which fre- Early postpartum period: Once the in- quent, painful, but poor-quality contrac- fant’s temperature has stabilized, mea- tions fail to accomplish effective cervical surements have been taken (length, effacement and dilation. Hypertonicity head and chest circumference, weight), usually occurs in the latent phase of la- and other prescribed care carried out, bor and most often is related to fetal the infant may be returned to the malpresentation and cephalopelvic dis- mother’s side (in its crib carrier). The proportion. nurse continues to assess the mother’s hypotonic l. Condition in which physical and psychological status after fewer than one to three contractions oc- delivery, checking the fundus, vulva, cur within 10 min. Hypotonicity usually and perineum according to policy; in- occurs after the woman has entered the spects the mother’s breasts and assists active phase of labor and most often is her with feeding (whether by breast or related to uterine overdistention, fetal bottle) and with measures to prevent macrosomia, multiple pregnancy, or lactation as desired; helps the mother to grand multiparity. deal with other responsibilities of moth- induction of l. The use of pharmaco- erhood; and carries out the mandated logical, mechanical, or operative inter- maternal teaching program, including ventions to initiate labor or to assist the providing written information for later progression of a previously dysfunc- review by the patient. In hospitals or tional labor. Induction may be consid- birthing centers, the nurse prepares the ered when the risks of expectant man- mother for early discharge to the home agement outweigh the benefits, placing setting and arranges for follow-up care the fetus and/or the mother in jeopardy. as needed and available. In many set- Among the more common indications tings, the nurse makes follow-up calls or are preeclampsia or eclampsia, prema- visits to the mother during the early ture rupture of membranes, fetal com- postpartum period or encourages her to promise, maternal medical diseases, call in with concerns, or she may receive chorioamnionitis, intrauterine fetal de- follow-up visits by a caregiver from her mise, postdate pregnancy, as well as health maintenance organization. The some psychosocial factors. Contraindi- mother may also be referred to support cations include placenta previa, vasa groups, such as the La Leche League, previa, umbilical cord prolapse, history Nursing Mothers’ Club, and others as of classic uterine incision, and trans- available in the particular community. verse fetal lie, as well as many relative active l. Regular uterine contrac- contraindications. SYN: artificial labor; tions that result in increasing cervical augmented labor. SEE: Nursing Diag- dilation and descent of the presenting noses Appendix. part. This encompasses the active phase of stage 1, as well as stages 2 and 3 of Oxytocin should be used only intra- labor. venously, using a device that per- arrested l. Failure of labor to proceed mits precise control of flow rate. While through the normal stages. This may be oxytocin is being administered, the fetal due to uterine inertia, obstruction of the heart rate and uterine contractions should pelvis, or systemic disease. be monitored electronically. short artificial l. Induction of labor. standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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instrumental l. Labor completed by diac rate and rhythm, blood pressure, mechanical means, such as the use of respiratory rate, auscultatory sounds, forceps. and FHRs are closely monitored to eval- missed l. 1. False l. 2. Labor in uate the patient’s response to the anti- which true labor pains begin but sub- dote. If no complications are present, side. This may be a sign of a dead fetus absolute bed rest is maintained or extrauterine pregnancy. throughout the infusion, with the pa- normal l. Progressive dilation and ef- tient in a left-lateral position or supine facement of the cervix with descent of with a wedge under the right hip to pre- the presenting part. vent hypotension. Antiembolism stock- obstructed l. Interference with fetal ings are applied, and passive leg exer- descent related to malposition, malpre- cises are performed. A daily fluid intake sentation, and cephalopelvic dispropor- of 2 to 3 L is encouraged to maintain ad- tion. equate hydration, and fluid intake and precipitate l. Labor marked by sud- output are measured. The patient is den onset, rapid cervical effacement and weighed daily to assess for overhydra- dilation, and delivery within 3 hr of on- tion. The patient is instructed in meth- set. ods to deal with stress. Health care pro- premature l. Preterm labor. viders should respond to parental preterm l. Labor that begins before concern for the fetus with empathy, but completion of 37 weeks from the last never with false reassurance. Fetal fi- menstrual period. The condition affects bronectin enzyme immunoassay may be 7% to 10% of all live births and is one of carried out on a sample of vaginal se- the most important risk factors for pre- cretions taken from the posterior vagi- term birth, the primary cause of peri- nal fornix; the patient should under- natal and neonatal mortality. Although stand that this test can help assess the associated risk factors do exist, in most risk of preterm delivery within 7 days cases the cause is unknown. SYN: pre- from the sampling date. As prescribed, mature labor. SEE: premature rupture a glucocorticoid is administered to stim- of membranes; prematurity; Nursing Di- ulate fetal pulmonary surfactant pro- agnoses Appendix. duction. Note: Treatment for active premature Patients who undergo in-house ther- labor is best managed in a regional peri- apy often receive magnesium sulfate, natal intensive care center, where staff which helps restore the patient’s beta-2 members are prepared to handle the re- receptor sensitivity (thus improving the quired care and treatment, and so that effectiveness of terbutaline) and de- the neonate can remain in the same set- crease uterine contractions. The patient ting as the mother, rather than being may be discharged on oral or subcuta- transferred alone for neonatal intensive neous tocolytic therapy. Intravenous care after delivery. therapy may be employed using a por- PATIENT CARE: In-hospital manage- table micropump that can deliver a ment: The patient is prepared for the basal rate or programmed intermittent use of cardiac, uterine, and fetal moni- bolus doses at predetermined times tors along with intravenous therapy. when the patient’s circadian rhythms Maternal vital signs and fetal heart rate are known to increase uterine activity. (FHR) are monitored. If prescribed a to- Home management: The plan for at- colytic agent (beta-adrenergic drug) is home care must target individuals administered intravenously; the infu- whom the woman can call upon to help sion rate is increased every 10 to 30 with home management. A social ser- min, depending on uterine response, but vice referral can help the family access never exceeds a rate of 125 ml/hr. Uter- available community and financial as- ine activity is monitored continuously; sistance. Home health care nurses as- vital signs and FHR are checked every sist the patient to carry out the plan, 15 min. Maternal pulse should not ex- provide ongoing emotional support, and ceed 140/min; FHR should not exceed evaluate fetal and patient response to 180 bpm. When counting respiratory therapy. rate, breath sounds are noted, and the The treatment regimen is reviewed lungs are auscultated at least every 8 with the family, and written instruc- hr. The patient is assessed for desired tions are provided to help those involved response and adverse effects to treat- to cooperate. The patient is maintained ment and is taught about symptoms she on bed rest (left-side, supine, with head may expect and should report. If signs on small pillow, feet flat or elevated) to of drug toxicity occur, the medication is increase uterine perfusion and to keep stopped. The intravenous line is kept fetal pressure off the cervix. The patient open with a maintenance solution, and usually is allowed out of bed only to go the prescribed beta-blocker as an anti- to the bathroom. The women’s physical dote is prepared and administered. The and psychological rest are the highest patient is placed in high Fowler’s posi- priority, as anxiety is known to compro- short tion, and oxygen is administered. Car- mise uterine blood flow. Paid or volun- standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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tary helpers must care for other chil- primary dysfunctional l. Abnormally dren and all household chores. The slow dilation of the cervix in the active patient’s tocolytic therapy (most fre- phase of labor; defined as less than 1.2 quently using terbutaline) is scheduled cm/hr in a nullipara and 1.5 cm/hr in a around the clock (with food if desired), multipara. SYN: protraction disorder. and the patient is taught about its ac- SEE: arrested l.; precipitate l. tion and adverse effects. The patient prodromal l. The initial changes that must be able to count her pulse, and is precede actual labor, usually occurring instructed to report a rate above 120/ 24 to 48 hr before the onset of labor. min. The patient also is taught about Some women report a surge of energy. symptoms to report (palpations, trem- Findings include lightening, excessive ors, agitation, nervousness) and how to mucoid vaginal discharge, softening and palpate for contractions twice each day. beginning effacement of the ripe cervix, Home uterine activity monitoring may scant bloody show associated with ex- be employed, with the patient or home pulsion of the mucus plug, and diarrhea. health care provider recording uterine prolonged l. Abnormally slow pro- activity for an hour twice daily. The gress of labor, lasting more than 20 hr. perinatal nurse analyzes the results. If SEE: dystocia. contractions exceed a predetermined prolonged latent phase l. Abnor- threshold, the patient is advised to mally slow progress of the latent phase, drink 8 to 12 ounces of water, rest, then lasting more than 20 hr in a nullipara empty her bladder and monitor uterine or 14 hr in a multipara. SEE: dystocia. activity for another hour. The process spontaneous l. Labor that begins can reduce unnecessary visits to the and progresses without pharmacologi- medical setting, and increase the pa- cal, mechanical, or operative interven- tient’s peace of mind. The patient is en- tion. couraged to drink water throughout the stage I l. SEE: labor; Nursing Diag- day to prevent dehydration and reduce noses Appendix. related uterine irritability. She also is stage II l. SEE: labor; Nursing Di- warned not to take over the counter agnoses Appendix. drugs without her obstetrician’s ap- trial of l. Permitting labor to continue proval. The patient is taught how to use long enough to determine if normal sedation, if prescribed. Avoidance of ac- vaginal birth appears to be possible tivities that could stimulate labor is (e.g., in vaginal birth after cesarean de- emphasized; these include sexual and livery). nipple stimulation. Personal hygiene is laboratorian (la˘b-ro˘-to˘r’e¯-ı˘n) A person reviewed, and the patient is made who works in a clinical or research lab- aware of signs of infection to report. A oratory (e.g., performing assays, prepar- nonstress test may be performed weekly ing or analyzing specimens, designing at home or in a medical setting, de- protocols, or managing workflow). pending on the acuity of the situation laboratory (la˘bЈra˘-torЉe¯) [L. laborato- and on maternal health factors (dia- rium] A room or building equipped for betes, pregnancy-induced hypertension scientific experimentation, research, [PIH]). The patient usually is provided testing, or clinical studies of materials, with a 24-hr phone link to perinatal fluids, or tissues obtained from patients. nurses in the health care system, who labret (la¯Јbre˘t) [L. labrum, lip] A deco- may contact her twice daily to discuss rative piercing through the central bot- her situation. She is taught what to do tom lip. in an emergency (bright red bleeding, labrocyte (la˘bЈro¯-sı¯t) [Gr. labros, greedy, membrane rupture, persisting contrac- ϩ kytos, cell] A mast cell. tions, decreased or absent fetal activity). labyrinth (la˘bЈı˘-rı˘nth) [Gr. labyrinthos, If an incompetent cervix has been diag- maze] 1. A series of intricate commu- nosed based on the patient’s history, in- nicating passages. 2. The inner ear, the sertion of a purse-string suture (cerclage) bony and vestibular labyrinths, which as reinforcement at 14 to 18 weeks ges- contain the receptors for hearing and tation may prevent premature labor. If equilibrium. SEE: illus. labor is inevitable, it is carried out as for bony l. Osseous l. a low-birth-weight, readily compromised ethmoidal l. The lateral mass of the fetus. During the postpartum period, ethmoid bone, which includes the su- care focuses on helping the family to un- perior and middle conchae and encloses derstand their infant’s special needs, and the ethmoid sinuses. to participate as fully as possible in care, membranous l. Vestibular l. or, in a worst-case scenario, to come to osseous l. The complex, hollow space terms with the baby’s death. In such a in the temporal bone that consists of the case, the family is assisted in their griev- vestibule, three semicircular canals, ing, with encouragement to hold the and cochlea, all filled with perilymph. swaddled infant, and look at pictures of SYN: bony labyrinth. the child if they are able. Psychological vestibular l. The vestibular (balance short counseling may be required. and equilibrium) portion of the mem- standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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SEMICIRCULAR CANALS BONY LABYRINTH

PERILYMPH VESTIBULAR BRANCH ACOUSTIC (8TH CRANIAL) COCHLEAR BRANCH NERVE MEMBRANOUS LABYRINTH

ENDOLYMPH

CRISTA

SACCULE

TYMPANIC CANAL AMPULLA COCHLEAR DUCT UTRICLE

VESTIBULAR CANAL

COCHLEA OVAL WINDOW ROUND WINDOW LABYRINTHS OF INNER EAR Arrows in cochlea indicate path of vibrations

branous labyrinth of the internal ear. It tral America. It is structurally similar has two divisions: to Paracoccidioides brasiliensis. The 1 the utricle and saccule, and yeast, like the disease, has several sci- 2 the semicircular ducts. entific names, including Loboa loboi and The vestibular labyrinth is filled with en- Paracoccidiodes loboii. dolymph and is suspended in the bony lacerate (la˘sЈe˘r-a¯t) [L. lacerare, to tear] labyrinth, which is filled with peri- To tear, as into irregular segments. lac- lymph. SYN: membranous labyrinth. erated (la˘sЈe˘-ra¯tЉe˘d), adj. labyrinthectomy (la˘b-ı˘-rı˘n-the˘kЈto¯-me¯) laceration (la˘sЉe˘-ra¯Јshu˘n) A wound or ir- [Љϩektome, excision] Excision of the regular tear of the flesh. lacerable labyrinth. (la˘sЈe˘r-a˘-b’l), adj. labyrinthine (la˘b-ı˘-rı˘nЈthı¯n) 1. Pert. to a l. of cervix Bilateral, stellate, or uni- labyrinth. 2. Intricate or involved, as a lateral tear of the cervix uteri caused by labyrinth. 3. Pert. to speech that wan- childbirth. ders aimlessly and unconnectedly from l. of perineum An injury of the peri- subject to subject, as seen in schizophre- neum caused by childbirth. If it extends nia. through the sphincter ani muscle, it is labyrinthitis (la˘bЉı˘-rı˘n-thı¯Јtı˘s) [Љϩitis, considered complete or fourth degree. inflammation] An inflammation (acute SEE: episiotomy. or chronic) of the labyrinth. Symptoms stellate l. A tear in the skin or in an include vertigo, vomiting, and nystag- internal organ caused by blunt trauma. mus. It may result from such conditions Several lines emanate outward from the as viral infections, bacterial infections, tear’s center. or head trauma. SEE: Me´nie`re’s disease; lacertus (la˘-se˘rЈtu˘s) [L., lizard] 1. The otitis interna. muscular part of the arm. 2. A muscular labyrinthotomy (la˘bЉı˘-rı˘n-tho˘tЈo¯-me¯) [Љ or fibrous band. ϩ tome, incision] Surgical incision into Lachesis muta (la˘-ke¯-sı˘s mooЈta) Bush- the labyrinth. master labyrinthus (la˘bЉı˘-rı˘nЈthu˘s) [L., Gr. la- Lachman test (la˘kЉma˘n) A test used to byrinthos, maze] A labyrinth. evaluate the integrity of the anterior lac (la˘k) [L.] 1. Milk. 2. Milky medicinal cruciate ligament of the knee. The ex- substance. aminer stands on the side being exam- Lacazia loboi (la˘-ko˘z’e¯-a˘lo¯’bo¯-ı¯, −lo¯-bo¯Ј, −e¯) ined and grasps the tibia at the level of [NL.] A spherical yeast that causes cu- the tibial tubercle while stabilizing the taneous and subcutaneous infections femur with the other hand. The patient known as Lobomycosis, Lobo’s disease, relaxes the leg while the examiner holds or keloidal blastomycosis, typically in the knee flexed at 25Њ to 30Њ and pulls short the tropical regions in South and Cen- forward on the tibia while stabilizing standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh laciniate 1287 lactate dehydrogenase base of rh

the femur. Excessive motion relative to lactacidemia (la˘k-ta˘sЉı˘-de¯Јme¯-a˘) [ЉϩЉ the opposite knee or no discernible end ϩ Gr. haima, blood] Excessive accu- point determine a positive result. mulation of lactic acid in the blood. It laciniate (la˘-sı˘nЈe¯-a¯t) [L. lacinia, fringe] occurs normally following strenuous Being jagged or fringed. and prolonged exercise. SYN: lactic ac- lacrim- Prefix indicating tear, lacrimal idemia. apparatus. lactaciduria (la˘kt-a˘-sı˘d-u¯ Јre¯-a˘) [ЉϩЉ lacrima (la˘kЈrı˘-ma˘) [L.] Tear fluid from ϩ Gr. ouron, urine] Lactic acid ex- eye. creted in the urine. lacrimal (la˘kЈrı˘m-a˘l) [L. lacrima, tear] lactagogue (la˘kЈta˘-go˘g) [ЉϩGr. ago- Pert. to the tears. SEE: lacrimal appa- gos, leading] Galactagogue. ratus. lactalbumin (la˘k-ta˘lЈbu¯-mı˘n) [Љϩal- lacrimal apparatus Structures concerned bumen, coagulated white of egg] The al- with the secretion and conduction of bumin found in milk and other dairy tears. It includes the lacrimal gland and products. its secretory ducts, lacrimal canaliculi, lactam (la˘kЈta˘m) An organic chemical lacrimal sac, and nasolacrimal duct, that contains the 9NH9CO group in which empties into the nasal cavity. a ring form. It is formed by the removal SEE: illus. of a molecule of water from certain Patency of the lacrimal duct may be amino acids. tested by placing a dilute solution of ␤-lactamase-resistant antibiotics (ba¯Јta˘- sugar in the conjunctival sac; if the duct la˘k-ta˘-ma¯z) SEE: under beta-lacta- is patent, the individual will report the mase-resistant antibiotics; beta-lacta- sensation of sweetness in the mouth; if mase resistant penicillin. not, the sugar will not be perceived. lactase (la˘kЉta¯s) [Љϩ−ase, enzyme] An lacrimation (la˘kЉrı˘-ma¯Јshu˘n) [L. lac- intestinal sugar-splitting enzyme con- rima, tear] The secretion and discharge verting lactose into dextrose and galac- of tears. tose; found in intestinal juice. SEE: en- test for l. Schirmer’s test. zyme; maltase; sucrase; sugar. lacrimator (la˘kЈrı˘-ma¯Љto˘r) A substance lactate (la˘kЈta¯t) 1. Any salt derived from that increases the flow of tears. lactic acid. 2. To secrete milk. lacrimatory (la˘kЈrı˘-ma˘-to¯Љre¯) Causing lactate dehydrogenase An enzyme that the production of tears. catalyzes the oxidation of lactate. It is lacrimotomy (la˘kЉrı˘-mo˘tЈo¯-me¯) [Љϩ found in a variety of tissues (lung, kid- Gr. tome, incision] Incision of lacrimal ney, heart, liver, blood) in slightly dif- duct. ferent forms called isoenzymes. Detec- lactacid (la˘k-Љta˘sЈı˘d) Lactic acid. tion of these isoenzymes in the

CONJUNCTIVA

LACRIMAL GLAND

LACRIMAL CANALS

LACRIMAL SAC

LACRIMAL DUCTS

NASOLACRIMAL DUCT

NASAL CAVITY

LACRIMAL APPARATUS short Anterior view of right eye standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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bloodstream is used in the diagnosis by way of the thoracic duct, to the left and management of a variety of ill- subclavian vein. SEE: lymph. nesses. SYN: lactic dehydrogenase. lactic (la˘kЈtı˘k) [L. lac, milk] Pert. to lactation (la˘k-ta¯Јshu˘n) [L. lactatio, a milk or lactic acid. sucking] 1. The production and release lactic dehydrogenase Lactate dehydro- of milk by mammary glands. 2. The pe- genase. riod of breastfeeding after childbirth, lactiferous (la˘k-tı˘fЈe˘r-u˘s) [Љϩferre, to beginning with the release of colostrum bear] Secreting and conveying milk. (the nutrient-rich substance that pre- lactifuge (la˘kЈtı˘-fu¯j) [Љϩfugare, to ex- cedes milk production) and continuing pel] 1. Stopping milk secretion. 2. An until the infant is weaned. Many hor- agent that stops milk secretion. monal factors are involved in lactation. lactigenous (la˘k-tı˘jЈe˘n-u˘s) [ЉϩGr. gen- The process depends on secretion of the nan, to produce] Producing milk. hormone prolactin by the pituitary lactinated (la˘kЈtı˘-na¯tЉe˘d) Containing or gland, but it begins only after the prepared with lactose, or milk sugar. marked decreases in estrogen and pro- lactivorous (la˘k-tı˘vЈor-u˘s) [Љϩvorare, gesterone that follow childbirth. Nurs- to devour] Living on milk. ing by the infant stimulates pulsatile in- lacto- (la˘k’to¯) [L. lac, lactis, milk] Com- creases in prolactin secretion. Oxytocin, bining form meaning milk (incl. dairy secreted by the hypothalamus, also con- products). tributes to the release of milk by stim- Lactobacillus (la˘k-to¯-ba˘-sı˘lЈu˘s) [Љϩba- ulating the contraction of muscular cells cillus, little rod] A genus of gram-posi- in the milk ducts and mammary glands. tive, anaerobic, non–spore-forming ba- DIET: The dietary needs of the cilli of the family Lactobacillaceae. They mother are increased during lactation, produce lactic acid from carbohydrates usually by about 500 kcal daily. In ad- and are responsible for the souring of dition, maternal needs for calcium, fo- milk. Some are part of normal flora. late, and other vitamins increase while L. acidophilus A species that pro- breastfeeding. SEE: breastfeeding; co- duces lactic acid by fermenting the sug- lostrum. ars in milk. It is found in milk and in l. amenorrhea method ABBR: LAM. the feces of bottle-fed infants and adults The method of causing decreased fertil- whose diets include a high milk content. ity in a woman by nursing a child for a It is also part of oral and vaginal flora. lengthy period (several years or more). L. bulgaricus A species found in fer- In general, the longer a woman breast- mented milk. Milk fermented with this feeds, the longer ovulation is delayed. organism is known as Bulgarian milk. For this method to work, a baby must be L. casei A species found in milk and exclusively breastfed on demand, cheese. around the clock. Once other food and L. helveticus A species found in drinks are added to the infant’s diet, Swiss cheese. this method is not considered reliable. lactocele (la˘kЈto¯-se¯l) [ЉϩGr. kele, tu- In addition, most breastfeeding women mor, swelling] Galactocele. ovulate before their first postpartum Lactococcus (la˘kЉto¯-ko˘kЈu˘s) A genus of menses and within 4 to 18 months after delivery. nonmotile, gram-positive cocci that l. suppression Inhibition of postpar- grow in pairs or short chains. Most or- tum production of breast milk, either if ganisms in the genus were previously the postpartum woman chooses not to grouped with the enterococci, lactoba- breastfeed or when she elects to cease cilli, and streptococci. They produce breastfeeding. Recommended actions large quantities of the L-isomer of lactic include avoiding local stimulation of the acid. Members of the species are used in breasts; wearing a tight-fitting bras- dairy industry, e.g., in the fermentation of cheeses. A few cause human disease. siere; applying ice packs; and adminis- Љ Ј tering mild over-the-counter analgesics, lactoferrin (la˘k to¯-fe˘r rı˘n) An enzyme re- such as acetaminophen or aspirin, to re- leased in phagocytosis by neutrophils duce discomfort. Manual expression of and macrophages that combines with milk is discouraged; although this ac- iron in the blood. As a result, the iron is tion may temporarily reduce the dis- unavailable to invading pathogens that comfort, it also stimulates further milk require iron for their reproduction. production. Breast engorgement usu- lactogen (la˘kЈto¯-je˘n) [L. lac, milk, ϩ ally resolves within a few days, and lac- Gr. gennan, to produce] Any substance tation ceases in 1 to 2 weeks. that stimulates milk production. SEE: lacteal (la˘kЈte¯-a˘l) [L. lacteus, of milk] A prolactin. lymphatic capillary in a villus of the human placental l. ABBR: HPL. A small intestine. Lacteals absorb fatty hormone produced by the placenta and acids and other fat-soluble end products released into maternal blood. It acts in of digestion. This fatty fluid is then the last stage of gestation to prepare the called chyle, which travels through the breasts for milk production. short larger intestinal lymphatic vessels and, lactogenic (la˘kЉto¯-ge˘nЈnı˘k) [ЉϩGr. standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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gennan, to produce] Inducing the secre- therapeia, treatment] Galactotherapy tion of milk. (2). lactoglobulin (la˘kЉto¯-glo˘bЈu¯-lı˘n) [Љϩ lactotroph (la˘kЈto¯-tro¯f) A prolactin pro- globulus, globule] A protein found in ducer. The term is typically used to de- milk. Casein and lactoglobulin are the note protactin-secreting cells or adeno- most common proteins in cow’s milk. mas in the pituitary gland. immune l. Antibodies present in the lactovegetarian (la˘kЉto¯-ve˘jЉe˘-ta˘rЈe¯-a˘n) colostrum. 1. Pert. to milk and vegetables. 2. One lactogogue (la˘kЈto¯-go˘gЉ) Galactogogue. who lives on a diet of milk, other dairy lactometer (la˘k-to˘mЈe˘-te˘r) [ЉϩGr. products, and vegetables. metron, measure] A device for deter- lactulose (la˘kЈtu¯-lo¯s) A synthetic disac- mining the specific gravity, and there- charide, 4-O-␤-D-galactopyranosyl-D- fore the richness of milk. fructofuranose, that is not hydrolyzed or lacto-ovo-vegetarian (la˘kЉto¯-o¯Љvo¯-ve˘jЉe˘- absorbed in humans. It is metabolized ta¯Јre¯-a˘n) A person consuming a vege- by bacteria in the colon with the pro- tarian diet that includes eggs and dairy duction of organic acids and is used to products. treat constipation and the encephalop- lactophosphate (la˘kЉto¯-fo˘sЈfa¯t) [Љϩ athy that develops in patients with ad- phosphas, phosphate] A salt derived vanced cirrhosis of the liver. The unab- jointly from lactic and phosphoric acids. sorbed sugar produces diarrhea, and the lactoprotein (la˘kЉto¯-pro¯Јte¯-ı˘n) [ЉϩGr. acid pH helps to contain ammonia in the protos, first] Any protein present in feces. milk. lacuna (la˘-kooЈna˘, −ku¯ Ј) pl. lacunae [L., lactorrhea (la˘k-to¯-re¯Јa˘) [ЉϩGr. rhoia, lacuna, pit, gap, deficiency] 1. An flow] The discharge of milk between empty space, gap, or hollow area. 2. The nursings and after weaning of offspring. space occupied by cells of calcified tis- SYN: galactorrhea. sues (e.g., cementocytes, chondrocytes, lactose (la˘k-to¯s) 1. A disaccharide that and osteocytes). 3. A focal loss of brain on hydrolysis yields glucose and galac- tissue due to a stroke involving a small tose. Bacteria can convert it into lactic penetrating artery in the brain. lacunar and butyric acids, as in the souring of (−na˘r), adj. milk. The milk of mammals contains 4% lacunae laterales Irregular divertic- to 7% lactose. Its presence in the urine ula on either side of the superior sagit- may be indicative of obstruction to flow tal sinus of the brain into which the of milk after cessation of nursing. Com- arachnoid villi project. mercial lactose is a fine white powder l. magna The largest pitlike recess in that will not dissolve in cold water. 2. A the fossa navicularis of the distal end of sugar, C11H22O11, obtained from evapo- the male urethra. ration of cow’s milk. It is used in man- l. pharyngis A pit at the pharyngeal ufacturing tablets and as a diluent. end of the eustachian tube. l. intolerance An inability to digest l. vasorum A space for passage of milk and some dairy products, leading femoral vessels to the thigh. to abdominal bloating, cramping, and venous l. A lateral pouch or divertic- diarrhea. The intolerance may be con- ulum of the superior sagittal sinus of genital or may begin in childhood, ado- the brain into which protrude arachnoid lescence, or young adulthood. villi that return cerebrospinal fluid to ETIOLOGY: A deficiency of the en- the venous circulation. zyme lactase, which digests lactose in lacune (la˘-koonЈ, −ku¯nЈ) [L. lacuna, pit, the small intestine, causes this intoler- gap, deficiency] Lacuna. ance. absorption l. Howship’s lacune. TREATMENT: Affected individuals Howship’s l. A pit or groove in bone should limit consumption of milk and where resorption or dissolution of bone other lactose-containing foods. Yogurt is occurring; usually contains osteo- or milk from which lactose has been re- clasts. SYN: absorption l. duced or eliminated may be substituted. intervillous l. A space in the placenta lactose tolerance test A test for defi- occupied by maternal blood and into ciency of lactase in the small intestine which fetal placenta villi project. that consists of the administration of a trophoblastic l. An irregular cavity weighed amount of lactose, followed by in the syntrophoblast that develops into successive measurements of blood glu- intervillous spaces or lacunae. SEE: in- cose at timed intervals. Low levels of tervillous lacuna. glucose indicate a lactase deficiency. l. of the urethra Any of several re- lactosuria (la˘k-to¯-su¯ Јre¯-a˘) [ЉϩGr. cesses in the mucous membrane of the ouron, urine] The presence of milk urethra, esp. along the floor and in the sugar (lactose) in the urine, a condition bulb. They are the openings of the ure- that occurs frequently during preg- thral glands. nancy and lactation. lacunula, lacunule (la˘-ku¯ Јnu¯-la˘, −nu¯l) short lactotherapy (la˘k-to¯-the˘rЈa˘-pe¯) [ЉϩGr. [L., little pit] A small or minute lacuna. standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh lacus 1290 Lamaze technique base of rh lacus (la¯Јku˘s) [L., lake] A collection of TREATMENT: Artificial tears or other fluid in a small hollow or cavity. ocular lubricants are needed to prevent l. lacrimalis Lacrimal lake. corneal ulceration. LAD left anterior descending (branch of nocturnal l. Failure of the eyelids to the left coronary artery). remain closed during sleep, which may LADA left acromion-dorsal-anterior fetal be due to chronic keratitis. position. laity (la¯Јı˘-te¯) [Gr. laos, the people] In- LADP left acromion-dorsal-posterior fetal dividuals who are not members of a par- position. ticular profession such as law, den- Lae¨nnec’s cirrhosis (la¯Љe˘-ne˘ksЈ) [Rene´T. tistry, medicine, or the ministry. H. Lae¨nnec, Fr. physician and the in- LAIV live attenuated influenza vaccine. ventor of the stethoscope, 1781–1826] SEE: under vaccine. Cirrhosis of the liver associated with LAK cell lymphokine-activated killer cell. chronic excessive alcohol ingestion. SEE: under cell. SYN: hobnail liver. SEE: liver, cirrhosis lake [L. lacus] 1. A small cavity of fluid. of. SEE: lacus. 2. The appearance of Lae¨nnec’s pearls Round gelatinous plasma after blood cells in it have bro- masses seen in asthmatic sputum. ken down, releasing their hemoglobin Lae¨nnec’s thrombus Globular thrombus pigment. in the heart. lacrimal l. The small pouch formed Laetrile (la¯Јe˘-trı˘l) Amygdalin; a glyco- by the junction of the conjunctiva at the side derived from pits or other seed medial canthus of the eye. Tears collect parts of plants, including apricots and in this area before they drain through almonds. Amygdalin contains sufficient the lacrimal canaliculi into the nasolac- cyanide to be fatal when taken in large rimal duct. The lacrimal lake can hold a doses. It has no known therapeutic or normal amount of tears, but when ex- nutritional value. There is no evidence cess tears are secreted (e.g., during cry- that it is effective in treating cancer. It ing), the tears overflow the lipid-coated is also known as vitamin B17. edge of the lower lids and spill onto the cheeks. SYN: lacus lacrimalis. Complications of Laetrile treat- venous l. 1. A small subcutaneous ment may include acute or chronic bleb filled with blood. It may be present cyanide poisoning. on the lips, mouth, or ears. 2. A lateral pouch or diverticulum of the superior Ј sagittal sinus of the brain into which Lafora, Gonzalo R (la˘-fo¯ ra˘) Spanish protrude arachnoid villi that return physician, 1887–1971. cerebrospinal fluid to the venous circu- L.’s bodies Cytoplasmic inclusion lation. bodies made of acid mucopolysaccha- LAL limulus amebocyte lysate. rides. They may be found in neuronal La Leche League (la˘-le˘Љcha¯le¯g) An or- tissues taken from patients with famil- ganization whose purpose is to promote ial myoclonic epilepsy. breastfeeding. Street address: 1400 N L.’s disease Familial progressive ep- Meacham Rd Schaumburg, IL 60173- ilepsy. 4808. Website: www.lalecheleague.org lag 1. The period of time between the ap- Ј ϩ plication of a stimulus and the resulting laliatry (la˘l-ı¯ a˘-tre¯) [Gr. lalia, talk, reaction. 2. The early period following iatria, therapy] The study and treat- ment of speech disorders and defects. bacterial inoculation into a culture me- Ј dium, characterized by slow growth. lallation (la˘-la¯ shu˘n) [L. lallatio] An in- SYN: lag phase; latent period. fantile form of speech in which the letter Ј “l” is incorrectly used or pronounced. lageniform (la˘-je˘n ı˘-form) [L. lagena, Љ Ј Љϩ flask, ϩ forma, shape] Flask-shaped. lalophobia (la˘l o¯-fo¯ be¯-a˘) [ phobos, Љ Ј fear] Fear of speaking. Lagochilascaris (la˘ go¯-kı¯-la˘s ka˘-rı˘s) [Gr. Ј Љϩ lago¯s, hare, ϩ cheilos, lip, ϩ askaris, laloplegia (la˘l-o¯-ple¯ je¯-a˘) [ plege, a intestinal worm] A genus of parasitic stroke] A paralysis of the speech mus- worms that may infect the skin, esp. in cles without affecting the action of the residents of or travelers to the Carib- tongue. bean. lalorrhea (la˘lЉo¯-re¯Јa˘) [Љϩrhoia, flow] lagophthalmos, lagophthalmus (la˘gЉo˘f- An abnormal flow of speech. tha˘lЈmo¯s, −mu˘s) [Gr. lagos, hare, ϩ Lamaze technique, Lamaze method (la˘- ophthalmos, eye] An incomplete clo- ma˘zЈ) [Fernand Lamaze, Fr. obstetri- sure of the palpebral fissure when an at- cian, 1890–1957] A method of psycho- tempt is made to shut the eyelids. This prophylaxis for childbirth in which the results in exposure and injury to the mother is instructed in breathing tech- bulbar conjunctiva and cornea. This niques that permit her to facilitate de- condition is caused by contraction of a livery by relaxing at the proper time scar of the eyelid, facial nerve injury, at- with respect to the involuntary contrac- ony of the orbicularis palpebrarum, or tions of abdominal and uterine muscu- short exophthalmos. lature. Those who are able to use the standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh lambda 1291 lamina base of rh

method require little if any anesthesia periosteal l. The bone lamella next to during delivery. SEE: labor. and parallel with the periosteum, form- lambda, ⌳, ␭ (la˘mЈda˘) [Gr.] 1. A letter ing the external portion of bone. in the Greek alphabet (⌳, ␭); also sig- vitreous l. Bruch’s membrane. nified by the letter L or l. 2. The point lamellar (la˘-me˘lЈa˘r) 1. Arranged in thin or angle of junction of the lambdoid and layers, plates or scales. 2. Pert. to the sagittal sutures. lamella. lambdacism (la˘mЈda˘-sı˘zm) [Gr. lamb- lameness Limping, abnormal gait, or dakismos] 1. Stammering of the “l” hobbling resulting from partial loss of sound. 2. An inability to pronounce the function in a leg. The symptom may be “l” sound properly. 3. Substitution of “l” due to maldevelopment, injury, or dis- for “r” in speaking. ease. lambdoid, lambdoidal (la˘mЈdoyd, la˘m- lamin (la˘Јmı˘n) A filament, intermediate doydЈa˘l) [Gr. lambda, ϩ eidos, form, in size between microtubules and micro- shape] Shaped like the Greek letter ⌳. filaments, that makes up a part of the lambert (la˘mЈbe˘rt) [Johann H. Lambert, skeletal structure of the nucleus of a Ger. physicist, 1728–1777] A unit of cell. brightness equal to that seen when a lamina (la˘mЈı˘-na˘) pl. laminae [L.] 1. A perfectly diffusing surface radiates or thin flat layer or membrane. 2. The flat- reflects one lumen of light per square tened part of either side of the arch of a centimeter. SEE: lumen (2). vertebra. Lambert-Eaton myasthenic syndrome alar l. The alar plate of the embryonic (la˘mЈbe˘rt-e¯Јtu˘n) [Edward Howard nervous system, which later develops Lambert, U.S. physiologist, 1915–2003; into sensory portions of the brain and Lee McKendree Eaton, U.S. physician, the dorsal horns of the gray matter of 1905–1958] An autoimmune syndrome the spinal cord. in which weakness of the proximal mus- alar l. of neural tube Alar plate. cles (e.g., around the shoulder and the anterior elastic l. Bowman’s mem- hip girdle), diminished reflexes, and au- brane. tonomic dysfunction are found. The syn- basal l. 1. The basal plate of the em- drome is often associated with small cell bryonic nervous system, which later de- carcinoma of the lung or other malig- velops into the ventral horns of the gray nancies. SYN: Eaton-Lambert syn- matter of the spinal cord. 2. A muco- drome. polysaccharide layer on the basal sur- lame [AS. lama] Disabled in one or more face of epithelial cells which separates limbs, esp. in a leg or foot, impairing them functionally from the underlying normal locomotion. connective tissue of the body. lamella (la˘-me˘lЈa˘) pl. lamellae [L., a lit- l. basalis choroideae Bruch’s mem- tle plate] 1. A thin layer, sheet, or brane. plate. 2. A medicated disk of gelatin in- basement l. The preferred term for a serted under the lower eyelid and thin layer of delicate noncellular mate- against the eyeball; used as a local ap- rial of a fine filamentous texture under- plication to the eye. lying the epithelium. Its principal com- bone l. Plates of collagen fibers, 3 to ponent is collagen. SYN: basal lamina; 7 ␮m thick, found in secondary (mature, basement membrane; hyaline mem- adult) bone and surrounded by cement- brane. ing substance, the mineralized bone ma- Bowman’s l. Bowman’s membrane. trix. Some lamellae are parallel to each l. cartilaginis cricoideae The poste- other. Other lamellae are aligned con- rior portion of the cricoid cartilage. centrically around a vascular canal — a l. choriocapillaris The middle layer structure known as a haversian system of the choroid, containing a dense mesh or osteon. of capillaries. SYN: Ruysch’s membrane. circumferential l. A layer of bone l. cribrosa sclerae The portion of the that underlies the periosteum. sclera forming a sievelike plate through concentric l. One of the cylindrical which pass fibers of the optic nerve to plates of bone surrounding a haversian the retina. canal. SYN: haversian l. dental l. A U-shaped internal growth enamel l. Microscopic cracks or cal- of the oral epithelium in the embryonic cification imperfections in the enamel maxillary and mandibular regions that surface of a tooth. They may be shallow forms into enamel organs which pro- or extend into the underlying dentin duce the teeth. SEE: enamel organ. and occur as a developmental defect or l. dura A radiographical term de- a microfracture caused by temperature scribing the compact bone (alveolar change or shearing forces. bone proper) that surrounds the roots of ground l. Interstitial lamella. teeth. In a state of health, it appears on haversian l. Concentric lamella. a radiograph as a dense radiopaque interstitial l. The bone lamella filling line. the irregular spaces within the haver- epithelial l. The epithelial layer cov- short sian system. SYN: ground l. ering the choroid layer of the eye. standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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l. fusca sclerae The layer of thin pig- and to induce cervical ripening. Haz- mented connective tissue on the inner ards associated with the use of seaweed surface of the sclera of the eye. include cervical lacerations, accidental interpubic fibrocartilaginous l. Part rupture of membranes, and infection. of the articulation of the pubic bones, laminarin (la˘mЉı˘-na¯Јrı˘n) A polysaccha- connecting the opposing surfaces of ride obtained from Laminaria species of these bones. seaweed. It consists principally of glu- l. papyracea A thin, smooth plate of cose residues. bone on the lateral surface of the eth- laminated (la˘mЈı˘n-a¯tЉe˘d) [L. lamina, moid bone; it forms part of the orbital thin plate] Arranged in layers or lami- plate. nae. perpendicular l. A thin sheet of bone lamination (la˘mЉı˘n-a¯Јshu˘n) Layer-like forming the perpendicular plate of the arrangement. ethmoid bone. It supports the upper laminectomy (la˘mЉı˘-ne˘kЈto¯-me¯) [Љϩ portion of the nasal septum. Gr. ektome, excision] The excision of a l. propria mucosae The thin layer of vertebral posterior arch, usually to re- areolar connective tissue, blood vessels, move a lesion or herniated disk. and nerves that lies immediately be- It is recommended only after conserv- neath the surface epithelium of mucous ative treatment (physical therapy, anti- membranes. inflammatory medication) has been ex- pterygoid l. One of the internal and hausted. Minimally invasive spine external laminae that make up the pter- surgery can be used to treat conditions ygoid process of the sphenoid bone. such as herniated or ruptured lumbar They are areas of attachment for the discs, bone spurs, synovial cysts, and muscles of mastication. lumbar spinal stenosis. Patients with a rostral l. A continuation of the ros- history of open spine surgery may be trum of the corpus callosum and the ter- poor candidates for minimal procedures minal lamina of the third ventricle of because of scar tissue. SEE: Nursing Di- the brain. agnoses Appendix. spiral l. A thin, bony plate projecting PATIENT CARE: Preoperative: The from the modiolus into the cochlear ca- patient’s knowledge of the procedure is nal, dividing it into two portions, the up- determined, misconceptions are cor- per scala vestibuli and lower scala tym- rected, additional information is pro- pani. Also called lamina spiralis. vided as necessary, and a signed in- suprachoroid l. The superficial layer formed consent form is obtained. A of the choroid consisting of thin trans- baseline assessment of the patient’s parent layers, the outermost adhering neurological function and of lower ex- to the sclera. SEE: lamina suprachoro- tremity circulation is documented. idea. SYN: suprachoroidea. Health care providers discuss postop- l. suprachoroidea The outermost erative care concerns, demonstrate ma- layer of the choroid. neuvers such as log-rolling, assure the terminal l. The thin sheet of tissue patient of the availability of pain medi- forming the anterior border of the third cations on request, and prepare the pa- ventricle. l. of vertebral arch One of the lami- tient for surgery according to the sur- nae extending from the pedicles of the geon’s or institutional protocol. vertebral arches and fusing together to Postoperative: Vital signs and neuro- form the dorsal portion of the arch. The vascular status (motor, sensory, and cir- spinous process extends from the center culatory) are monitored; antiembolism of these laminae. stockings or pneumatic dressings are l. vitrea Bruch’s membrane. applied, and anticoagulants are given if laminae (la˘mЈı˘-ne¯) Pl. of lamina. prescribed. The dressing is inspected for laminar (la˘-mЈı˘-na˘r) Made up of or pert. bleeding or cerebrospinal fluid leakage; to laminae. either problem is documented and re- l. air flow Filtered air moving along ported immediately, and the incision is separate parallel flow planes to surgical redressed as necessary. The patient is theaters, patient rooms, nurseries, bac- maintained in a supine position, with teriology work areas, or food prepara- the head flat or no higher than 45Њ ac- tion areas. This method of air flow helps cording to the surgeon’s preference, for to prevent bacterial contamination and the prescribed time (usually 1 to 2 hr), collection of hazardous chemical fumes then repositioned side to side every 2 hr in areas where they would pollute the by log-rolling the patient with a pillow work environment. between the legs to prevent twisting Laminaria digitata (la˘m-ı˘-na¯rЈe¯-a˘dı˘j-ı˘- and hip adduction and to maintain spi- ta¯Јta˘) A genus of kelp or seaweed that, nal alignment. Deep breathing (with when dried, has the ability to absorb use of an inspirometer in most cases) is water and expand with considerable encouraged, and assistance is provided force. It has been used to dilate the uter- with range-of-motion, gluteal muscle short ine cervical canal in induced abortion setting, and quadriceps setting exer- standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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cises. Adequate assistance should be invasion, and metastasis of tumor cells, available when the patient is permitted and cellular attachment. SEE: glycopro- to dangle his or her feet, stand, and tein; extracellular matrix. walk in the early postoperative period. laminitis (la˘m-ı˘n-ı¯Јtı˘s) [ЉϩGr. itis, in- Prescribed anti-inflammatory, muscle- flammation] The inflammation of a relaxant, and antibiotic agents are ad- lamina. ministered. Noninvasive measures to laminopathy (la˘-mı˘n-o˘pЈa˘-the¯) Any dis- prevent and relieve incisional discom- ease caused by defective construction of fort are provided in addition to pre- lamins within cells. scribed analgesics. Fluid balance is laminotomy (la˘mЉı˘-no˘tЈo¯-me¯) [ЉϩGr. monitored by administering prescribed tome, incision] A division of one of the intravenous fluids and by assessing vertebral laminae. urine output. The patient is encouraged lamp [Gr. lampein, to shine] A device for to void within 8 to 12 hr postsurgery and producing and applying light, heat, ra- is assessed for bladder distention, which diation, and various forms of radiant en- may indicate urinary retention. Cathe- ergy for the treatment of disease, reso- terization is used only after other mea- lution of impairments, or palliation of sures to promote voiding have been at- pain. tempted. The abdomen is auscultated infrared l. A lamp that develops a for return of bowel sounds, and ade- high temperature, emitting infrared quate oral nutrition is provided as pre- rays; a heat lamp. The rays penetrate scribed. Patients who have undergone only a short distance (5 to 10 mm) into minimally invasive procedures are out the skin. Its principal effect is to cause of bed and resuming some normal activ- heating of the skin. ities (e.g., showering, engaging in activ- slit l. A lamp so constructed that an ities around the house) within a day or intense light is emitted through a slit; two of surgery. Responses vary and may used for examination of the eye. SEE: depend on the patient’s personality, illus. presurgical activity level, and overall health. Specific restrictions on postop- erative activity should be outlined with the patient in detail at the time of dis- charge. Rehabilitative and home care: Inci- sional care techniques are taught to the patient and family, and the importance is stressed of checking for signs of infec- tion (increased local pain and tender- ness, redness, swelling, and changes in the amount or character of any drain- age) and of reporting these to the sur- geon. A gradual increase in the patient’s activity level is encouraged. Any pre- scribed exercises (pelvic tilts, leg rais- ing, toe pointing) are reviewed, and pre- scribed activity restrictions are reinforced. Restrictions usually include sitting for prolonged periods, lifting heavy or moderately heavy objects, or bending over. Proper body mechanics are taught to lessen strain and pressure on the spine: these include maintaining SLIT LAMP EXAMINATION proper body alignment and good posture and sleeping on a firm mattress. In- volvement in an exercise program, be- sun l. Ultraviolet lamp. ginning with gradual strengthening of ultraviolet l. A lamp that produces abdominal muscles, is encouraged after light with a wavelength in the range of 6 weeks. Walking is encouraged. The 180 to 400 nm. It is used to treat certain patient should schedule and keep a fol- skin conditions such as psoriasis or T- low-up appointment with the surgeon cell lymphoma, to promote wound heal- and communicate any concerns to the ing by destroying bacteria, and to tan surgeon (if necessary) before that visit. the skin. Ultraviolet lamps produce laminin (la˘mЈi-nı˘n) A glycoprotein found light within specific ranges: ultraviolet- in all basement membranes that is in- A (UV-A) lamps generate light having a volved in the binding of cells to the ex- wavelength of 320 to 400 nm; ultravio- tracellular matrix, particularly to type let-B (UV-B) produces light in the range intravenous collagen. It contributes to of 290 to 320 nm; ultraviolet-C (UV-C) the growth and cellular organization of has a wavelength of 180 to 290 nm. short tissues and is involved in angiogenesis, SYN: sun lamp. standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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soft tissue l. An area or point on a Patients and operators must wear soft tissue used as a point of reference ultraviolet-resistant goggles during for measurements of the body or its parts. treatment. Overexposure to ultraviolet land mines Explosive devices placed in or light produces burning and blistering of on the ground to injure, kill, or destroy the skin and may predispose patients to humans, animals, or equipment passing skin cancers. over or near them. These are activated on contact. They remain active after Wood’s l. Wood’s filter. armed conflict has ceased and, if they lance (la˘ns) [L. lancea] 1. A two-edged are not removed, can detonate years surgical knife. 2. To incise with a lancet later, causing unexpected traumatic in- or other cutting instrument. jury and death. Lance-Adams syndrome (la˘ns-a˘dЈa˘mz) Landry-Guillain-Barre´ syndrome Myoclonus occurring after any disease (la˘nЈdre¯-ge¯-ya˘Ј) Guillain-Barre´ syn- or condition that limits the flow of blood drome. and oxygen to the brain. Landsteiner’s classification (la˘ndЈstı¯- Lancefield classification (la˘nsЈfe¯ld) [Re- ne˘rz) [Karl L. Landsteiner, Austrian- becca Craighill Lancefield, U.S. bacte- born U.S. biologist, 1868–1943; Nobel riologist, 1895–1981] A classification prize winner in medicine in 1930] A of hemolytic streptococci into various classification of blood types designating groups according to antigenic structure. O, A, B, and AB based on the presence lancet (la˘nЈse˘t) [L. lancea, lance] 1. A of antigens on red blood cells. pointed surgical knife with two edges. Lane’s kinks (La¯nz) [Sir William Ar- 2. A spring-loaded or manual blade used buthnot Lane, Brit. surgeon, 1856– to make a limited skin incision as for 1943] Bending or twisting of the last collection of blood specimen. few centimeters of the ileum with exter- lancinating (la˘nЈsı˘-na¯tЉı˘ng) [L. lanci- nal adhesions between the folded loops nare, to tear] Sharp or cutting, as pain. of intestines. This may cause intestinal L and A Abbreviation for the reaction of obstruction. the pupils of the eye to light and accom- Langerhans’ islands (la˘ngЈge˘r-ha˘nz) Is- modation. lets of Langerhans. Landau-Kleffner syndrome (kle˘fЈne˘r) [William M. Landau, Frank R. Kleffner, Langer’s lines (la˘ngЈe˘rz) [Carl (Ritter American neurologists] A rare disease von Edenberg) Langer, Austrian anato- in which children (usually between the mist, 1819–1887] The structural ori- ages of 3 and 7) lose the ability to un- entation of the fibrous tissue of the skin, derstand spoken language and to ex- forming the natural cleavage lines that, press themselves. Children with this though present in all body areas, are disorder have seizures and sometimes visible only in certain sites such as the hyperactivity or other behavioral or psy- creases of the palm. These lines are of chiatric disorders. Lost language skills particular importance in surgery. Inci- are sometimes recovered by affected sions made parallel to them make a children in adolescence. SYN: acquired much smaller scar upon healing than epileptiform aphasia; infantile acquired those made at right angles to the lines. aphasia. SEE: illus. Landau reflex (la˘nЈdo¯, dow) An infantile Langhans’ layer (la˘ngЈha˘ns) [Theodor reflex in which the body flexes when the Langhans, Ger. pathologist, 1839– head is passively flexed forward in a 1915] A cellular layer present in the prone position. It appears normally at 3 chorionic villi of the placenta. SYN: cy- months and is absent in children with totrophoblast. cerebral palsy and gross motor retar- language The spoken or written words or dation. symbols used by a population for com- landmark A recognizable skeletal or soft munication. tissue structure used as a reference language bias The tendency for editors point in measurements or in describing and readers to pay greater attention to the location of other structures. SEE: scientific studies reported in English cephalometry; craniometry. than to those studies written in other bony l. A structure or spot on a bone languages. used as a reference for measurement. languor (la˘ngЈge˘r) [L. languere, to lan- cephalometric l. A bony point that is guish] A feeling of weariness or ex- used in living persons or radiographs for haustion as from illness; lack of vigor or measurements of the head or face or ori- animation; lassitude. entation of the head in certain positions. laniary (la˘nЈe¯-a¯Љre¯) [L. laniare, to tear to craniometric l. A bony point or area pieces] Adapted or designed for tear- on the skull used for measurements or ing, as the canine teeth. orientation of the skull. lanolin (la˘nЈo˘-lı˘n) [L. lana, wool] The radiographic l. A cephalometric, cra- purified, fatlike substance obtained niometric, or soft tissue landmark used from the wool of sheep; used as an oint- short for orientation or measurements. ment base. standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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LANGER’S LINES

anhydrous l. Wool fat containing not form pert. to the flank and to operations more than 0.25% water; used as an oint- through the abdominal wall. ment base that has the ability to absorb laparocele (la˘pЈa˘-ro¯-se¯l) [Љϩkele, tu- water. mor, swelling] An abdominal hernia. Lanoxin SEE: digoxin. laparocholecystotomy (la˘pЉa˘r-o¯-ko¯lЉe¯- lanthanum (la˘nЈtha˘-nu˘m) SYMB: La. A sı˘s-to˘tЈo¯-me¯) [Љϩchole, bile, ϩ kys- metallic element; atomic weight tis, bladder, ϩ tome, incision] An in- 138.906; atomic number 57. It is one of cision into the gallbladder through the a group of elements called lanthanides. abdominal wall. lantibiotic (lanЈtı¯-bı¯-o˘t-ı˘k) Any peptide laparocolectomy (la˘pЉa˘-ro¯-ko¯-le˘kЈto¯-me¯) antibiotic whose chemical structure in- [Љϩkolon, colon, ϩ ektome, excision] cludes a bridge maintained by the rare Colectomy. amino acid lanthionine. Subtilin and laparocolostomy (la˘pЉa˘r-o¯-ko¯-lo˘sЈto¯-me¯) nisin are examples of lantibiotics. [ЉϩЉϩstoma, mouth] The forma- lanuginous (la˘-nu¯ Јjı˘n-u˘s) Covered with tion of a permanent opening into the co- lanugo. lon through the abdominal wall. lanugo (la˘-nu¯ Јgo¯) [L. lana, wool] laparocolotomy (la˘pЉa˘r-o¯-ko¯-lo˘tЈo¯-me¯) 1. Downy hair covering the body. 2. Fine An incision into the colon via the ab- downy hairs that cover the body of the dominal wall. fetus, esp. when premature. The pres- laparocystectomy (la˘Љpa˘-ro¯-sı˘s-te˘kЈto¯- ence and amount of lanugo aids in esti- me¯) [Љϩkystis, bladder, ϩ ektome, mating the gestational age of preterm excision] The removal of an extrauter- infants. The fetus first exhibits lanugo ine fetus or a cyst through an abdominal between weeks 13 and 16. By gesta- incision. tional week 20, it covers the face and laparocystotomy (la˘pЉa˘r-o¯-sı˘s-to˘tЈo¯-me¯) body. The amount of lanugo is greatest An incision of the abdomen to remove between weeks 28 and 30. As the third the contents of a cyst or an extrauterine trimester progresses, lanugo disappears fetus. from the face, trunk, and extremities. laparoenterostomy (la˘pЉa˘-ro¯-e˘nЉte˘r- LAO left anterior oblique position. o˘sЈto¯-me¯) [Љϩenteron, intestine, ϩ short laparo- [Gr. lapara, flank] Combining stoma, mouth] The formation of an ar- standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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tificial opening into the intestine lopian tubes and ovaries through an ab- through the abdominal wall. dominal incision. laparoenterotomy (la˘pЉa˘r-o¯-e˘nЉte˘r-o˘tЈo¯- laparosalpingotomy (la˘pЉa˘r-o¯-sa˘l-pı˘n- me¯) [ЉϩЉϩtome, incision] An go˘tЈo¯-me¯) [ЉϩЉϩtome, incision] opening into the intestinal cavity by in- Incision of a fallopian tube through an cision through the loins. abdominal incision. SYN: celiosalpin- laparogastroscopy (la˘pЉa˘-ro¯-ga˘s-tro˘sЈko¯- gectomy. pe¯) [Љϩgaster, belly, ϩ skopein, to laparoscope (la˘pЈa˘-ro¯-sko¯pЉ)[Љϩsko- examine] Inspection of the inside of the pein, to examine] An endoscope de- stomach through an abdominal incision. signed to permit visual examination of laparogastrostomy (la˘pЉa˘r-o¯-ga˘s-tro˘sЈto¯- the abdominal cavity. SEE: illus. me¯) [ЉϩЉϩstoma, mouth] The surgical formation of a permanent gas- SURGEON tric fistula through the abdominal wall. SYN: celiogastrostomy. LAPAROSCOPE Љ Ј ABDOMINAL laparogastrotomy (la˘p a˘-ro¯-ga˘s-tro˘t o¯- WALL me¯) [ЉϩЉϩtome, incision] An in- INTESTINAL LOOPS cision into the stomach through the ab- OMENTUM dominal wall. SYN: celiogastrotomy. laparohepatotomy (la˘pЉa˘r-o¯-he˘pЉa˘-to˘tЈo¯- me¯) [Љϩhepar, liver, ϩ tome, inci- sion] An incision of the liver through the abdominal wall. laparohystero-oophorectomy (la˘pЉa˘r-o¯- hı˘sЉte˘r-o¯-o¯Љo˘f-o¯-rekЈto¯-me¯) [ЉϩЉϩ oon, ovum, ϩ phoros, bearer, ϩ ek- PERITONIUM SPINE AND SPINAL CANAL tome, excision] The removal of the uterus and ovaries through an abdomi- LAPAROSCOPE nal incision. laparoscopic gastric banding (la˘pЉa˘r-a˘- laparohysteropexy (la˘pЉa˘r-o¯-hı˘sЈte˘r-o¯- sko˘pЈı˘k) A bariatric surgical treatment pe˘ks-e¯) [ЉϩЉϩpexis, fixation] Ab- in which a tight band is placed around dominal fixation of the uterus. the upper stomach, restricting its vol- laparohysterosalpingo-oophorectomy ume and increasing the sense of satiety (la˘pЉa˘r-o¯-hı˘sЉte˘r-o˘-sa˘l-pı˘nЉgo¯-o¯Љo˘-fo¯- after a meal. Relative to other forms of re˘kЈto¯-me¯) [Љϩhystera, womb, ϩ bariatric surgery, gastric banding is less salpinx, tube, ϩ oon, ovum, ϩ pho- effective; patients who undergo gastric ros, bearer, ϩ ektome, excision] The banding achieve less weight loss. removal of the uterus, fallopian tubes, laparoscopic vertical gastrectomy A and ovaries through an abdominal in- bariatric surgical treatment in which a cision. large portion of the stomach is removed, laparohysterotomy (la˘pЉa˘r-o¯-hı˘sЉte˘r- leaving a 60- to 80-ml gastric tube. The o˘tЈo¯-me¯) [ЉϩЉϩtome, incision] greater curvature of the stomach is re- Surgery of the uterus through an ab- moved during the procedure. The small dominal incision. SEE: cesarean section. residual stomach tube prevents overeat- laparoileotomy (la˘pЉa˘r-o¯-ı˘l-e¯-o˘tЈo¯-me¯) [Љ ing by creating a feeling that the stom- ϩ L. ileum, ileum, ϩ Gr. tome, inci- ach is full after a small meal. (The op- sion] An abdominal incision into the il- eration may also affect serum levels of eum. hormones like ghrelin, which influence laparomyomectomy (la˘pЉa˘r-o¯-mı¯Љo¯- hunger and satiety.) The operation is me˘kЈto¯-me¯) [ЉϩЉϩoma, tumor, ϩ purely restrictive and does not produce ektome, excision] Abdominal excision of malabsorption of nutrients. It is rela- a muscular tumor. tively easy to perform compared with laparonephrectomy (la˘pЉa˘r-o¯-ne˘-fre˘kЈto¯- other forms of bariatric surgery. Com- plications of the procedure include nau- me¯) [Љϩnephros, kidney, ϩ ektome, sea, vomiting, and gastric leaks. excision] Renal excision through the laparoscopy (la˘p-a˘r-o˘sЈko¯-pe¯) [Љϩsko- loin. Ј Љϩ pein, to examine] Abdominal explora- laparorrhaphy (la˘p-a˘-ror a˘-fe¯) [ tion with an endoscope. rhaphe, seam, ridge] Suture of a wound laparosplenectomy (la˘pЉa˘r-o¯-sple¯n- in the abdominal wall. SYN: celiorrha- e˘kЈto¯-me¯) [Љϩsplen, spleen, ϩ ek- phy. tome, excision] Abdominal excision of laparosalpingectomy (la˘pЉa˘r-o¯-sa˘l-pı˘n- the spleen. jekЈto¯-me¯) [Љϩsalpinx, tube, ϩ ek- laparosplenotomy (la˘pЉa˘r-o¯-sple¯n-o˘tЈo¯- tome, excision] Excision of a fallopian me¯) [ЉϩЉϩtome, incision] Incision tube through an abdominal incision. of the spleen through the abdominal laparosalpingo-oophorectomy (la˘pЉa˘r-o¯- wall. sa˘l-pı˘nЉgo¯-o¯Љo˘f-o¯-re˘kЈto¯-me¯) [ЉϩЉϩ laparotomy (la˘p-a˘r-o˘tЈo¯-me¯) [Љϩtome, oon, ovum, ϩ phoros, bearer, ϩ ek- incision] The surgical opening of the short tome, excision] The removal of the fal- abdomen. SYN: celiotomy. standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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PATIENT CARE: Preoperative: The ing as a tray or platform over the lap to patient’s knowledge of the surgery is de- support the hands and arms or to per- termined, misconceptions are clarified, mit manual activities. and a signed informed consent form is Laplace, law of (la˘-pla¯sЈ) [Pierre-Simon obtained. A baseline assessment of all Laplace, Fr. scientist, 1749–1827] A body systems is conducted. The patient law stating that pressure within a tube is encouraged to express feelings and is inversely proportional to the radius. concerns, and reassurance is offered. The larger the diameter of a tubular Preoperative teaching should focus on structure, the less chance that it will explaining the procedure, postoperative rupture when subjected to an increase care, and expected sensations. Preop- in pressure. erative blood tests (including complete lard [L. lardum, fat] Purified fat from blood counts and serum chemistries), the hog. The sole nutrient is fat; a 100- urinalysis, ECG, and chest X-ray usu- g portion contains 902 kcal. ally are carried out, and consultations benzoinated l. Lard containing 1% with appropriate specialists are con- benzoin, used as a vehicle for certain ducted. Physical preparation of the pa- types of topically applied medicines. tient is carried out according to insti- lardaceous (la˘r-da¯Јshu˘s) [L. lardum, fat] tutional or surgeon’s protocol regarding Resembling lard; waxy, fatty. diet; removal of abdomen and pubic large for gestational age ABBR: LGA. area hair; enemas, douches, administra- Term used of a newborn whose birth tion of intravenous fluids, measure- weight is above the 90th percentile on ments of vital signs and intake and out- the intrauterine growth curve. Such ba- put. Antiembolic measures are applied bies should be monitored for signs of hy- as prescribed. poglycemia during the first 24 hr after Postoperative: Vital signs and dress- birth. ing status are monitored; the latter in- large loop excision of the transformation cludes checking any drains in place and zone ABBR: LLETZ. Obtaining a bi- for the presence of vaginal bleeding if opsy of the uterine cervix in patients in applicable. Ventilatory status is as- whom the colposcopic examination or sessed by auscultating for adventitious Pap smear indicates the area is abnor- or decreased breath sounds, and respi- mal. The tissue is obtained by use of an ratory toilet (deep breathing, coughing, electrically heated wire loop. This pro- incentive spirometry, oral hygiene, and cedure is used in treating noninvasive repositioning) is provided as deter- carcinoma of the cervix. SYN: loop elec- mined by the patient’s response. The trode excision procedure. nurse assists the patient to use nonin- L-arginine An amino acid promoted as a vasive pain relief measures and pre- dietary supplement and sometimes em- scribed analgesia for pain relief or mon- ployed by athletes to increase energy itors patient-controlled analgesia for levels, human growth hormone levels, effectiveness. Fluid balance is moni- or performance in sports. tored, and prescribed fluid and electro- Larmor frequency In magnetic resonance lyte replacement therapy is adminis- imaging (MRI), the frequency of the ra- tered. The patient is encouraged to void dio wave that will resonate with all the after surgery; the bladder assessed for protons in the nucleus of a given ele- distention, which may indicate urinary ment. The Larmor radio frequency in- retention; and catheterization is insti- duces the magnetic resonance used to tuted only when nursing measures are create MRI images. unsuccessful. The abdomen is auscul- Laron syndrome [Z. Laron, contempo- tated for the return of bowel sounds, rary Israeli physician] Primary insen- and a high-protein, high vitamin C diet sitivity or resistance to the effects of is initiated following clear to full liquids growth hormone. It is a common cause as prescribed. Leg mobilization, turn- of dwarfism. Affected individuals have ing, and early ambulation are encour- high levels of circulating growth hor- aged, to promote gastrointestinal activ- mone, but do not make insulin-like ity and prevent venous thrombosis. The growth factor-1 (IGF-1). They can be hospital staff initiates early discharge treated with IGF-1. SYN: growth hor- planning, which includes carrying out mone insensitivity syndrome. patient teaching focused on incisional Larsen syndrome [Loren Joseph Larsen, care, obtaining adequate nutrition, com- Am. orthopedic surgeon, b. 1914] A plications to report (e.g., nausea, vom- rare autosomal disorder characterized iting, fevers, chills, constipation or by multiple joint dislocations and flat- wound dehiscence), and activity re- tening of the face with widely spaced sumption and restrictions; arranging eyes, among other findings. referral for home care as appropriate; larva (larЈva˘) [L., mask] 1. General and ensuring that the patient has term applied to the developing form of scheduled (and plans to keep) a follow- an insect after it has emerged from the up appointment with the surgeon. egg and before it transforms into a short lap board A wheelchair attachment serv- pupa, from which it emerges as an standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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adult. 2. The immature forms of other for and agreeable to the particular pa- invertebrates such as worms. larval tient (e.g., simple sign language, flash (la˘rЈva˘l), adj. cards, magic slate, alphabet board) are l. currens A type of larva migrans. explained. The postoperative setting The organism, Strongyloides stercoralis, and care are described to the patient, in- travels subcutaneously at the rate of cluding assessment procedures and sen- about 10 cm an hour rather than at the sations; and equipment used (suction- slow rate of larva migrans. ing, nasogastric [NG] tube feeding, cutaneous l. migrans A skin lesion laryngectomy tube care, wound drain- characterized by a tortuous elevated red age). Other functional losses that may line that progresses at one end while be expected are explored (loss of smell, fading out at the other. It is caused by nose-blowing, whistling, gargling, sip- the subcutaneous migration of the lar- ping, sucking on a straw). The patient vae of certain nematodes, esp. Ancylo- is encouraged to discuss emotions, sen- stoma braziliense and A. caninum, that sations, and thoughts; and the use of fa- occur as parasitic infections in humans. milial, psychological, or spiritual forms visceral l. migrans Toxocariasis. of support is presented. Informed con- larvate (la˘rЈva¯t) [L. larva, mask] Hid- sent is obtained. den, concealed, as a hidden symptom. Postoperative: If a partial laryngec- larvicide (la˘rЈvı˘-sı¯d) [Љϩcaedere, to tomy is performed, a tracheostomy tube kill] An agent that destroys insect lar- will be in place until edema subsides, vae. and the patient should not use his voice larviphagic (la˘rЉvı˘-fa¯Јjı˘k) [ЉϩGr. until permitted to do so and then should phagein, to eat] Consuming larva, as is whisper until healing is complete. If a done by certain fish. total laryngectomy is performed, a lar- laryngalgia (la˘r-ı˘n-ga˘lЈje¯-a˘) [Gr. larynx, yngectomy tube (shorter and thicker larynx, ϩ algos, pain] Laryngeal than a tracheostomy tube) will be in pain. place until the stoma heals (7 to 10 laryngeal (la˘r-ı˘nЈje¯-a˘l) [Gr. larynx, lar- days). Vital signs are monitored, espe- ynx] Pert. to the larynx. cially ventilatory rate and effort, as well laryngeal framework surgery Thyro- as level of consciousness, arterial blood plasty. gas values, peripheral oxygen satura- laryngeal tracheal airway ABBR: LTA. tion levels, and the status of dressings An airway that can be blindly inserted and drains, including the posterior area. into the hypopharynx to use when ad- The airway is assessed for patency; the vanced airway control is needed during tracheostomy or laryngectomy tube is procedures that require brief anesthe- gently (but not deeply) suctioned to pro- sia. It consists of an airway tube with a tect the suture line, as are the oral cav- proximal cuff, which holds the middle of ity and nose, as needed. Crust formation the tube in place at the base of the is prevented by increasing humidity and tongue, and a distal cuff to fix the end fluid intake, and frequent oral hygiene of the tube in the trachea. and assistance in managing saliva are provided. The patient usually is posi- tioned on one side, with the head ele- It should not be used in patients at vated to 30 to 45 degrees. Support is high risk of aspiration. provided to the patient’s neck posteri- orly during movement. The patient is laryngectomee (la˘rЉı˘n-je˘kЈto¯-me¯) [Љϩ taught to provide support by interlock- ektome, excision] An individual whose ing fingers of both hands behind his larynx has been removed. neck when moving. Fluid balance is laryngectomy (la˘rЉı˘n-je˘kЈto¯-me¯) [Љϩ monitored, prescribed replacement ektome, excision] Removal of all or part therapy is provided, and urination is en- of the larynx, to treat cancers or other couraged. The patient is assessed for diseases of the larynx. The procedure early complications such as respiratory may cure the lesion if it is confined to distress due to edema, infection, dehy- the organ, or it may be used to palliate dration, and hemorrhage (remembering symptoms. Common side effects of the to check the posterior aspect of the neck, surgery are loss of voice, gastroesopha- as well as dressings, drains, and vital geal reflux, and adjustment disorders or signs); and for later ones such as fistula depression as a result of the changes in formation, tracheal stenosis, and ca- body image produced by the operation. rotid artery rupture. If the carotid ar- SEE: Nursing Diagnoses Appendix. tery ruptures, pressure is applied to the PATIENT CARE: Preoperative: The site immediately, assistance called for, patient is prepared for vocal and airway and the patient quickly returned to the changes and for other functional losses operating theater for carotid ligation. If after surgery. Explanations are supple- a fistula occurs, continued tube feeding mented with diagrams and samples of is necessary to prevent food leakage required equipment. Postsurgical com- that would interfere with healing (over short munication methods most appropriate a period of weeks to months). Tracheal standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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stenosis requires fitting the patient ally pain on phonation and deglutition. with tracheal/laryngectomy tubes that It may be caused by improper use or are gradually increased in size until a overuse of the voice, exposure to cold tracheal opening of adequate size can be and wet, extension from infections in achieved. Protein-rich, high vitamin C nose and throat, inhalation of irritating nutrition is provided, via the prescribed vapors and dust, or systemic diseases route (usually NG tube feeding ini- such as whooping cough or measles. tially), to aid healing. Frequent oral hy- TREATMENT: Treatment includes vo- giene is provided and encouraged as cal rest, liquid or soft diet, steam inha- part of self-care. Noninvasive measures lations, and codeine or nonnarcotic and prescribed analgesics to relieve cough suppressants for pain and cough. pain are provided. When the wound If the laryngitis is viral, no specific ther- drainage system is removed, dressings apy exists; if bacterial, appropriate an- are checked for any further drainage, tibiotics should be given. and the wound redressed according to atrophic l. Laryngitis leading to di- protocol. The patient is allowed time for minished secretion and atrophy of the communication and is reassured that mucous membrane. Symptoms are a verbal communication ability will be tickling sensation in the throat, hoarse- reestablished through tracheoesopha- ness, cough, and dyspnea when the geal puncture, esophageal speech, or ex- crusts are thick and accumulate on the ternal mechanical or electronical voice vocal cords, narrowing the breathing boxes. Professional staff supports the aperture. Inhalants and medicated patient and family through their grief sprays should be used to loosen the over losses (including loss of voice, whis- crusts, along with strict attention to as- tling, sucking ability, sense of smell and sociated nose and throat pathology. taste, nose blowing, activities such as chronic l. A type of laryngitis caused swimming) and damage to self-image by a recurrent irritation, or following and self-esteem. The patient is prepared the acute form. It is often secondary to for possible follow-up therapies, such as sinus or nasal pathology, improper use radiation and chemotherapy and ad- of the voice, excessive smoking or drink- verse effect as well as their manage- ing, or neoplasms. The patient experi- ment are discussed. Patient education ences a tickling in the throat, huskiness also should include stoma care activities of the voice, and dysphonia. The treat- (including the need to limit exposures to ment involves correcting the preexisting dusts, fumes, and vapors). Information nose and throat pathology, discontinu- is also provided about the management ing alcohol and tobacco use, and avoid- of colds and respiratory illnesses, the re- ing excessive use of the voice. moval of crust or mucus from the stoma, croupous l. Laryngitis occurring the need for warming and humidifica- mainly in infants and young children tion of inhaled air, and the risk of post- and characterized by a barky cough, operative tracheal stenosis. A list of the hoarseness, and stridor. resources in the community should be diphtheritic l. Invasion of the larynx provided for support, counseling, and by diphtheria, usually with formation of further education. Patients are encour- a membrane. aged to join local branches of groups membranous l. Laryngitis charac- such as the American Speech-Learning- terized by inflammation of the larynx, Hearing Association, American Cancer with the formation of a false, nondiph- Society, National Association of Laryn- theritic membrane. gectomee Clubs, or Lost Chord Club. A posterior l. Reflux laryngitis. rapid return to employment is encour- reflux l. Hoarseness, throat clearing, aged. Tobacco smokers and alcohol and alterations in voice quality thought users are encouraged to seek help in to be the result of injury to the posterior quitting. vocal folds from reflux of acids from the laryngismal (la˘rЉı˘n-jı˘sЈma˘l) [Љϩ−is- stomach through the esophagus. SYN: mos, condition] Concerning or resem- posterior laryngitis. bling laryngeal spasm. syphilitic l. A rare, chronic form of laryngismus (la˘rЉı˘n-jı˘sЈmu˘s) [Љϩ−is- laryngitis produced by secondary or ter- mos, condition] Spasm of the larynx. tiary involvement of the larynx by syph- laryngitic (la˘r-ı˘n-jı˘tЈı˘k) [Gr. larynx, lar- ilis. ynx] 1. Resulting from laryngitis. tuberculous l. Laryngitis secondary 2. Rel. to laryngitis. to infection with Mycobacterium tuber- laryngitis (la˘r-ı˘n-jı¯Јtı˘s) [Љϩitis, inflam- culosis. Infectious granuloma may be mation] Inflammation of the larynx. present in the interarytenoid area, vocal SEE: croup; Nursing Diagnoses Appen- cords, epiglottis, or false cords. dix. laryngo- [Gr. larynx, larynx] Combining acute l. Acute congestive laryngitis; form pert. to the larynx. inflammation of laryngeal mucosa and laryngocele (la˘r-ı˘nЈgo¯-se¯l) [Љϩkele, tu- the vocal cords. It is characterized by mor, swelling] A congenital air sac con- short hoarseness and aphonia and occasion- nected to the larynx. Its presence is nor- standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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mal in some animals but abnormal in plassein, to form] Plastic surgery of the humans. larynx. laryngocentesis (la˘r-ı˘nЉgo¯-se˘n-te¯Јsı˘s) [Љ laryngoplegia (la˘-rı˘ngЉgo¯-ple¯Јje¯-a˘) [Љϩ ϩ kentesis, puncture] Incision or punc- plege, stroke] Paralysis of the laryngeal ture of the larynx. muscles. laryngofissure (la˘r-ı˘ngЉgo¯-fı˘shЈu¯r) [Љϩ laryngorhinology (la˘r-ı˘nЉgo¯-rı¯n-o˘lЈo¯-je¯) L. fissura, a cleft] The operation of [Љϩrhis, nose, ϩ logos, word, rea- opening the larynx by a median line in- son] The branch of medical science con- cision through the thyroid cartilage. cerned with diseases of the larynx and laryngogram (la˘-rı˘ngЈgo¯-gra˘m) [Љϩ nose. gramma, something written] A radio- laryngorrhagia (la˘rЉı˘n-go¯-ra¯Јje¯-a˘) [Љϩ graph of the larynx. rhegnynai, to flow forth] Laryngeal laryngograph (la˘r-ı˘ngЈo¯-gra˘f) [Љϩ hemorrhage. graphein, to write] A device for making laryngorrhea (la˘rЉı˘n-go¯-re¯Јa˘) [Љϩ a record of laryngeal movements. rhoia, flow] Excessive discharge of la- laryngography (la˘rЉı˘n-go˘gЈra˘-fe¯) 1. A de- ryngeal mucus. scription of the larynx. 2. Radiography laryngoscleroma (la˘r-ı˘nЉgo¯-skle˘-ro¯Јma˘) of the larynx using a radiopaque con- [Љϩskleros, hard, ϩ oma, tumor] trast medium. Scleroma affecting the larynx. laryngologist (la˘rЉı˘n-go˘lЈo¯-jı˘st) [Љϩlo- laryngoscope (la˘r-ı˘nЈgo¯-sko¯p) [Љϩsko- gos, word, reason] A specialist in lar- pein, to examine] An instrument con- yngology. sisting of a blade and a fiberoptic light laryngology (la˘rЉı˘ng-go˘lЈo˘-je¯) The spe- source, used to examine the larynx (e.g., cialty of medicine concerned with the during endotracheal intubation). Љ Ј Љϩ pharynx, throat, larynx, nasopharynx, laryngoscopic (la˘r ı˘n-go¯-sko˘p ik) [ and tracheobronchial tree. skopein, to examine] Pert. to observa- laryngomalacia (la˘r-ı˘ngЉgo¯-ma˘-la¯Јshe¯-a˘) tion of the interior of the larynx with the [Љϩmalakia, softness] A softening of aid of a small long-handled mirror. SEE: the tissues of the larynx. laryngoscopy. Љ Ј Љϩ laryngoscopist (la˘rЉı˘ng-go˘sЈko¯-pı˘st) [Љ laryngometry (la˘r ı˘n-go˘m e˘-tre¯) [ ϩ metron, measure] The systematic skopein, to examine] An individual trained in laryngoscopy. measurement of the larynx. Љ Ј laryngoparalysis (la˘r-ı˘nЉgo¯-pa˘r-a˘lЈı˘-sı˘s) laryngoscopy (la˘r ı˘n-go˘s ko¯-pe¯) Visual [Љϩparalyein, to disable at one side] examination of the interior of the voice box (the larynx) to determine the cause Paralysis of the muscles of the larynx. of hoarseness, obtain cultures, remove a laryngopathy (la˘rЉı˘n-go˘pЈa˘-the¯) [Љϩ foreign body, manage the upper airway, pathos, disease] Any disease of the lar- or take biopsies of potentially malignant ynx. lesions. laryngopharyngeal (la˘r-ı˘nЉgo¯-fa˘r-ı˘nЈje¯- Љϩ PATIENT CARE: Short-acting intra- a˘l) [ pharynx, throat] Rel. jointly venous sedation or anesthesia is admin- to the larynx and pharynx. istered along with oxygen. Vital signs laryngopharyngeal reflux The backward and cardiac status are monitored flow of gastric contents into the voice throughout the procedure. After the box and throat. It may cause vocal cord procedure, the patient is placed in the damage, hoarseness, and habitual semi-Fowler position, and vital signs throat clearing. are monitored until stable. Oral intake laryngopharyngectomy (la˘r-ı˘nЉgo¯-fa˘r-ı˘n- is withheld until the patient’s swallow- je˘kЈto¯-me¯) [ЉϩЉϩektome, excision] ing reflex has returned, usually within Surgical removal of the larynx and 2 to 8 hr. An emesis basin is provided pharynx. It is usually only performed for saliva. Sputum is inspected for for cancers of the head and neck. blood. Excessive bleeding is reported. laryngopharyngeus (la˘-rı˘ngЉgo¯-fa˘-rı˘nЈje¯- Application of an ice collar helps to min- u˘s) The muscle that constricts the in- imize edema; subcutaneous crepitus ferior pharynx. around the face or neck should be re- laryngopharyngitis (la˘r-ı˘nЉgo¯-fa˘r-ı˘n- ported immediately because it may in- jı¯Јtı˘s) [ЉϩЉϩitis, inflammation] dicate tracheal perforation. The patient Inflammation of the larynx and phar- should not cough or clear the throat for ynx. at least 24 hr to minimize irritation. laryngopharynx (la˘r-ı˘nЉgo¯-fa˘rЈı˘nks) [Gr. Smokers who undergo laryngoscopy larynx, larynx, ϩ pharynx, throat] should be encouraged to quit; prepara- Hypopharynx. tion for the procedure and after-proce- laryngophony (la˘rЉı˘n-go˘fЈo¯-ne¯) [Љϩ dure care provide “teachable moments.” phone, voice] Voice sounds heard in auscultating the pharynx. 1. Visualization of the larynx is laryngophthisis (la˘rЉı˘ng-go˘fЈthı˘-sı˘s) [Љ associated with aerosolization of ϩ phthisis, a wasting] Tuberculosis of upper airway secretions. Standard pre- the larynx. cautions and droplet precautions are re- short laryngoplasty (la˘r-ı˘nЈgo¯-pla˘sЉte¯) [Љϩ quired during the procedure to limit the standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh laryngoscopy 1301 larynx base of rh spread of infectious diseases such as se- EPIGLOTTIS vere acute respiratory distress syndrome (SARS) or tuberculosis. HYOID 2. Laser safety precautions must be em- BONE ployed when lasers are used. THYROID CARTILAGE

direct l. Laryngoscopy with a laryn- geal speculum or laryngoscope. CRICOTHYROID indirect l. Laryngoscopy with a mirror. MEMBRANE laryngospasm (la˘r-ı˘nЈgo¯-spa˘zm) [Љϩ VOCAL spasmos, a convulsion] Spasm of the la- CORDS ryngeal muscles. CRICOID laryngostenosis (la˘r-ı˘ngЉgo¯-ste˘-no¯Јsı˘s) [Љ CARTILAGE ϩ stenosis, a narrowing] Stricture of TRACHEAL the larynx. CARTILAGES compression l. Stricture of the lar- ynx owing to outside causes such as ab- A B scess, tumor, or goiter. occlusion l. Stricture of the larynx LARYNX owing to congenital bands or mem- (A) anterior view, (B) midsagittal section branes, foreign bodies, tumors, scarring following ulceration as in diphtheria and tertiary syphilis, penetrating membrane and moved by muscles. The wounds, or corrosive fluid. Patients ex- cartilages include three single (cricoid, perience dyspnea, esp. on inspiration thyroid, and epiglottic) and three paired and exertion, often accompanied by stri- (arytenoid, corniculate, and cuneiform). dor. Treatment depends on the cause. The thyroid cartilage pushes soft tissue Tracheotomy is often necessary. forward, forming the Adam’s apple. The laryngostomy (la˘r-ı˘n-go˘sЈto¯-me¯) [Љϩ extrinsic muscles include the omohyoid, stoma, mouth] Establishing a permanent sternohyoid, sternothyroid, and several opening through the neck into the larynx. others; intrinsic muscles include the crico- laryngostroboscope (la˘rЉı˘n-go¯-stro¯Јbo¯- thyroid, external and internal thyroary- sko¯p) [Љϩstrobos, whirl, ϩ skopein, tenoid, and transverse and oblique aryte- to view] An instrument for inspecting noid. The cavity of the larynx contains two vibration of the vocal cords. pairs of folds—the ventricular folds (false laryngotomy (la˘r-ı˘n-go˘tЈo¯-me¯) [Љϩ vocal cords) and the vocal folds (true vocal tome, incision] Incision of the larynx. cords)—and is divided into three regions: inferior l. Surgical incision of the lar- the vestibule, ventricle, and inferior en- ynx through the cricoid cartilage. trance to the glottis. An opening between median l. Surgical incision of the lar- the true vocal folds forms a narrow slit, ynx through the thyroid cartilage. the rima glottidis or glottis. subhyoid l. Surgical incision of the NERVES: The larynx is innervated larynx through the thyroid membrane. from the interior and external branches SYN: superior l. of the superior laryngeal nerve. superior l. Subhyoid laryngotomy. BLOOD SUPPLY: The larynx is sup- laryngotracheal (la˘-rı˘ngЉgo¯-tra¯Јke¯-a˘l) [Љ plied by the inferior thyroid, a branch of ϩ tracheia, trachea] Concerning the the thyroid axis, and by the superior thy- larynx and trachea. roid, a branch of the external carotid. laryngotracheitis (la˘r-ı˘nЉgo¯-tra¯-ke¯-ı¯Јtı˘s) foreign bodies in l. An inhaled or as- [ЉϩЉϩitis, inflammation] Inflam- pirated solid object, such as a piece of mation of the larynx and trachea. meat, hard candy, safety pin, or coin, in laryngotracheobronchitis (la˘-rı˘ngЉgo¯- the larynx. Any aspirated object poses tra¯Љke¯-o¯-bro˘ng-kı¯Јtı˘s) [ЉϩЉϩbron- an imminent risk of airway obstruction. chos, windpipe, ϩ itis, inflammation] SYMPTOMS: Symptoms may include Inflammation of the larynx, trachea, coughing, choking, dyspnea, fixed pain, and bronchi. SEE: croup. or loss of voice. laryngotracheotomy (la˘r-ı˘nЉgo¯-tra¯-ke¯- PATIENT CARE: If the patient is able o˘tЈo¯-me¯) [ЉϩЉϩtome, incision] In- to speak or cough, the rescuer should cision of the larynx with section of upper not interfere with the patient’s attempts tracheal rings. to expel the object. If the patient is un- larynx (la˘rЈı˘nks) pl. larynges [Gr.] A able to speak, cough, or breathe, the res- musculocartilaginous organ at the up- cuer should apply the Heimlich maneu- per end of the trachea, below the root of ver 6 to 10 times rapidly in succession. the tongue, lined with ciliated mucous Using air already in the lungs, the membrane, that is part of the airway thrusts create an artificial cough to pro- and the vocal apparatus. SEE: illus. pel the obstructing object out of the air- ANATOMY: The larynx consists of nine way. If the patient loses consciousness, short cartilages bound together by an elastic carefully assist him or her to the ground standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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in a supine (face up) position. Next the signs should be posted indicating that a la- rescuer should begin CPR since com- ser is being used; equipment must be pressions have been shown to be effec- checked before the procedure; conventional tive in clearing an obstruction. With endotracheal tubes must be wrapped with each time attempt to ventilate, the res- aluminum foil tape or flexible metallic en- cuer should first look in the mouth to see dotracheal tubes insulated with silicone if there is an object that can be pulled may be used; skin preparation solution out of the airway with gloved fingers. may not contain combustible agents; and Previously chest thrusts were taught for towels draped around the site must be kept an obese or pregnant patient or a child wet. The laser equipment must be moved with a foreign body airway obstruction. carefully, to avoid jarring the mirrors out To simplify this procedure the Emer- of alignment. Alcohol-based skin prepara- gency Cardiac Care Guidelines 2005 tions should not be used. recommend all patients receive chest compressions following CPR. For an in- fant, the rescuer uses back slaps before argon l. A gas-produced light (in the chest thrusts. Direct laryngoscopy and blue and green visible light spectrum) the use of Magill forceps may be re- with a wavelength spectrum of 488 nm quired to remove a foreign object. If the to 633 nm, which coagulates tissues, is object cannot be readily removed with used in photodynamic therapy, and can these measures, an emergency cricoth- be absorbed by oxyhemoglobin in blood yrotomy, or emergency tracheotomy may vessels. Argon lasers have been used to be required. SEE: Heimlich maneuver. treat skin lesions, bleeding ulcers, he- laser (la¯Јze˘r) Acronym for light amplifi- mangiomas, periodontal disease, glau- cation by stimulated emission of radia- coma, retinal diseases, and other con- tion. It is a device that emits intense ditions. heat and power at close range. The in- carbon dioxide l. ABBR: CO2 laser. strument converts various frequencies A gas-produced colorless light with a of light into one small, extremely in- wavelength of 10,600 nm (infrared), tense unified beam of a single frequency used, for example, in dermatological or wavelength radiation. The laser can surgeries to remove scars, wrinkles, and be focused on a very small target. La- solar skin damage. It can also be used sers can be used surgically in a wide va- as a scalpel in stereotactic neurosurger- riety of ways. They influence cellular ies, gynecological surgeries, and many chemistry (the “photochemical” effects other applications. of lasers). They damage tissues by gen- PATIENT CARE: Laser precautions erating heat (e.g., producing coagula- must be observed. The patient is given tion, the “photothermal” effects). They support by answering questions and ex- can drill into, cavitate, or explode tis- plaining the need for eye covering dur- sues (“photomechanical” effects). They ing the procedure. The procedure is doc- can ablate tissues after transforming umented in a laser log. them into plasma. In addition to their cutaneous l. Any of several lasers surgical uses, lasers can be used for di- (e.g., argon, CO2, etc.) employed for cos- agnosis (e.g., by illuminating cells or tis- metic and plastic surgery, including the sues, as in fluorescence); and they have treatment of pigmented lesions, wrin- a vast number of laboratory applica- kles, vascular malformations, and other tions. Lasers have many treatment ap- cosmetic skin surface irregularities. plications. In ophthalmology, they are diode l. A compact laser designed used in treating cataracts, diabetic ret- with semiconductors, which has many inopathy, macular degeneration, and medical applications, including use in retinal detachment; in cardiology, to va- skin, eye, urological, and other surger- porize arterial obstructions; in derma- ies. Wavelengths are from 800 to 1000 tology, to obliterate blood vessels and to nm. remove warts, skin cancers, nevi, excess PATIENT CARE: Care involves gen- tissue, and tattoos; in gynecology, to re- eral support, giving explanations, and move vulval lesions, including genital answering questions. Equipment must warts; in gastroenterology, to control be checked and regulations followed, bleeding in the gastrointestinal tract; esp. those that involve fire safety. The and in oral surgery and dentistry, to re- surgeon is given assistance, as needed. move tumors. Many kinds of lasers are dye l. A laser whose energy is applied used depending upon the wavelength in pulses, primarily to manage skin le- and power required, including argon, sions. Wavelengths are 510 nm for carbon dioxide, copper vapor, dye, exci- green, and 577 nm to 600 nm for yellow. mer, helium-neon, ion, krypton, neo- PATIENT CARE: Care involves giving dymium:yttrium-aluminum garnet, and general emotional support, explana- ruby lasers. tions, and answering questions regard- ing the procedure. The equipment is Laser safety precautions must be checked, and all rules are observed. The short observed. For example, warning needs of the surgeon are anticipated, standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh laser 1303 LATCH score base of rh

and the procedure is recorded in the la- sible agent, an arenavirus, is spread to ser log. people after contact with infected ro- excimer l. An ultraviolet laser used dents or their excretions. Each year, ap- clinically to remove tissue from the cor- prox. 300,000 people are infected. nea (e.g., in LASIK surgery) or to re- SYMPTOMS: Patients have abrupt move plaque from arteries. This rare onset of high fever that is continuous or gas (halide) energy source laser breaks intermittent and spiking, with general- chemical bonds instead of destroying ized myalgia, chest and abdominal pain, tissue with heat; it penetrates less than headache, sore throat, cough, dizziness 1 mm into tissue. Halide combines with with flushing of the face, conjunctival an active medium (an excited dimer), injection, nausea, diarrhea, and vomit- from which it derives its name. The di- ing. Hemorrhagic areas of the skin and meric media are excited, emitting laser mucous membranes may appear on the energy. The chemical composition of the fourth day. Mortality of those in Africa medium determines the ultraviolet with this disease varies from 16% to wavelength. The four most popularly 45%. used are: the argon fluoride (ArF) laser TREATMENT: Ribavirin given in the at 193 nm, the krypton fluoride (KrF) at first week of illness and continued for 10 248 nm, the xenon chloride (XeCl) at days has been very effective in reducing 308 nm, and the xenon fluoride (XeFl) the death rate. This medicine should at 351 nm. also be given orally for 10 days prophy- grid l. A laser that scatters light en- lactically to those who have been per- ergy across the macula; used to treat cutaneously exposed to the virus. Pa- many eye diseases, including diabetic tients are isolated in special isolation retinopathy. units that filter the air leaving the room surface-enhanced l. desorption-ion- and maintain negative pressure. All ization ABBR: SELDI. A technique sputum, blood, excreta, and objects that used to separate and image molecules the patient has contacted are disin- (e.g., DNA or proteins) in biological fected. SEE: Standard Precautions Ap- samples. Molecules are captured on a pendix. protein chip, then ionized and imaged. lassitude (la˘sЈı˘-tu¯d) [L. lassitudo, wea- This technique can be used to map the riness] Weariness; exhaustion. molecules in samples of blood or other last menstrual period ABBR: LMP. The body fluids. date of the first day of menstruation be- yttrium-aluminum-garnet l. ABBR: fore a presenting illness or the advent of YAG laser. A laser with a crystal made pregnancy-related amenorrhea; used in of yttrium, aluminum, and garnet that estimating the expected date of deliv- can be used for skin resurfacing, or tis- ery. SEE: Naegeli’s rule. sue penetration in oral, urological, oph- LAT licensed athletic trainer. thalmic, cardiac, orthopedic, or other latah (la˘Јta˘) A behavior identified in applications. The depth of the penetra- Southeast Asian women marked by im- tion of the laser energy, its tissue ab- itation, swearing, repetitive speech, and sorption, and tissue-sparing character- obedient gestures. It may be provoked istics vary with the materials used as by startling, tickling, or frightening af- additives to the crystal, such as erbium, fected persons. Some researchers be- holmium, or neodymium. lieve it is a social convention rather PATIENT CARE: Care involves gen- than a psychiatric or neurological ill- eral support, giving explanations, and ness. answering questions. All equipment latanoprost (la˘-ta˘n’o¯-pro˘st) A prosta- must be checked and all rules observed. glandin agonist used as an ocular hy- The nurse assists the surgeon as nec- potensive and an antiglaucoma agent. It essary. is administered as eye drops to manage laser tissue welding (we˘ld’ı˘ng) To bring glaucoma or to lower intraocular pres- the edges of a wound together with heat sure. generated by a laser. latch, latch-on The attachment of the Lase`gue’s sign (la˘-se˘gzЈ) [Ernest C. baby’s mouth to the mother’s nipple. Ef- Lase`gue, Fr. physician, 1816–1883] In fective and comfortable latch-on is a lumbar disk disease, pain that radiates crucial element in successful breast- into the leg after the hips and knees are feeding. flexed and the knee is extended. SYN: latchkey children Children who have a Bragard test. key to their home, needed for when they LASIK Laser assisted in situ keratomileu- return home when no adult is present to sis. supervise them. These children are at a Lasix (la¯Јsı˘ks) SEE: furosemide. higher risk of accidents, abusing drugs, Lassa fever (la˘sЈsa˘) [Lassa, city in Af- and smoking cigarettes. rica] A potentially lethal viral illness LATCH score An assessment tool to eval- marked by hemorrhage, extreme mus- uate the effectiveness of early breast- cle pain, and in some cases shock. It is feeding. A numerical score of 0, 1, or 2 short contracted solely in Africa. The respon- is assigned to the five letters of the ac- standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

late luteal phase dysphoric top of rh disorder 1304 latrine base of rh

ronym: L-latching of infant onto the lateral (la˘tЈe˘r-a˘l) [L. lateralis] Pert. to breast, A-amount of audible swallow- the side. ing, T-type of nipple, C-comfort of lateral geniculate body One of two bodies mother, H-help needed by mother to forming elevations on the lateral por- hold baby to breast. Lower scores (Ͻ5) tion of the posterior part of the thala- can indicate the need for assistance for mus. Each is the termination of afferent better success at breastfeeding. fibers from the retina, which it receives late luteal phase dysphoric disorder through the optic nerves and tracts. SEE: premenstrual dysphoric disorder. lateralis (la˘tЉe˘r-a¯Јlı˘s) [L.] Located away latency (la¯Јte˘n-se¯) [L. latens, lying hid- from the mid-plane of the body. den] State of being concealed, delayed, laterality (la˘tЉe˘r-a˘lЈı˘-te¯) Rel. to one side dormant, inactive, or inapparent. of the body, i.e., the left or right; used, sleep l. The amount of time between e.g., to specify which side of the body or reclining in bed and the onset of sleep. brain is dominant. latency period The time from the stimu- crossed l. Mixed dominance of body lus to the response of the tissue stimu- parts, e.g., preferring to use the left arm lated. for throwing a ball but the right leg for latent 1. Lying hidden. 2. Quiet; not ac- kicking it. tive. dominant l. Preferential dominance l. content In psychoanalysis, that and use of the parts of one side of the part of a dream or unconscious mental body such as the eye, arm, leg, or hand. content that cannot be brought into the laterodeviation (la˘tЉe˘r-o¯-de¯Љve¯-a¯Јshu˘n) objective consciousness through any ef- [Љϩdeviare, to turn aside] Deviation fort of will to remember. or displacement to one side. latent heat The caloric or heat energy ab- lateroduction (la˘tЉe˘r-o¯-du˘kЈshu˘n) [Љϩ sorbed by matter changing from solid to ducere, to lead] Movement to one side, liquid or from liquid to vapor with no esp. of the eye. change in temperature. lateroflexion (la˘tЉe˘r-o¯-fle˘kЈshu˘n) [Љϩ l.h. of fusion The heat required to flexis, bending] Bending or curvature convert 1 g of a solid to a liquid at the toward one side. same temperature. For example, the lateroposition (la˘tЉe˘r-o¯-po¯-zı˘shЈu˘n) [Љϩ process of converting 1 g of ice at 0ЊCto positio, position] Displacement to one water at 0ЊC requires 80 cal, and until side. it is completed there will be no rise in lateropulsion (la˘tЉe˘r-o¯-pu˘lЈshu˘n) [L. lat- the temperature. eralis, pert. to side, ϩ pulsus, driving] l.h. of vaporization The heat re- In cerebellar and labyrinthine disease, quired to change 1 g of a liquid at its the involuntary tendency to fall to one boiling point to vapor at the same tem- side. perature. The latent heat of steam is laterotorsion (la˘tЉe˘r-o¯-torЈshu˘n) [Љϩ 540 cal; therefore, when steam cools to torsio, a twisting] Twisting to one side. liquid, each gram gives out 540 cal. This lateroversion (la˘tЉe˘r-o¯-ve˘rЈshu˘n) [Љϩ explains why a scald from steam is versio, a turning] A tendency or a turn- much more severe than one caused by ing toward one side. boiling water. latex (la¯Јte˘ks) A viscous, aqueous solu- latent period 1. The time between stim- tion of hydrocarbons, adsorbed proteins, ulation and the resulting response. ash, and resin produced mostly by trop- SYN: lag. 2. The time during which a ical trees and used in the manufacture disease is supposed to be existent with- of rubber products, e.g., surgical gloves. out manifesting itself; period of incuba- lathyrism (la˘thЈı˘-rı˘zm) [Gr. lathyros, tion. 3. The time from exposure to ion- vetch] A neurotoxic disorder caused by izing radiation to the first visible sign of eating the grass pea, Lathyrus sativus. the effects. Its hallmarks are irreversible muscular late-phase reaction Inflammation of any paralysis and spasticity. part of the body caused by the release of lathyrogen (la˘thЈı˘-ro¯-je˘n) [Љϩgennan, cytokines; leukotrienes B4, C4, and D4; to produce] Something that produces and prostaglandin D2, occurring ap- lathyrism. prox. 6 hr after the body’s initial re- Latino (lah-te¯nЈo¯) 1. Pert. to Latin- sponse to an antigen, during a type I hy- American language, culture, or ethnic- persensitivity response. Late-phase ity. 2. A person of Latin-American or reactions play a significant role in pro- Spanish-speaking ancestry. longing illnesses such as asthma after latitude (la˘tЈı˘-toodЉ, −tu¯dЉ) In radiology, the initial, immediate histamine-based a range of exposure that would produce response has subsided. These are a technically correct radiograph. treated with and prevented by the use latrine (la˘-tre¯nЈ) [L. latrina] A toilet, of corticosteroids, such as prednisone, particularly one in a military camp. and other drugs. pit l. A type of latrine installed out- laterad (la˘tЈe˘r-a˘d) [L. latus, side, ϩ ad, doors and used where it is impractical toward] Toward a side or lateral as- to provide a standard, flushing-type toi- short pect. let. The structure may be manufactured standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh Latrodectus 1305 lavage base of rh

and installed so that odors and flies are retinal degeneration, polydactyly, and minimized. deformity of the skull. The condition is Latrodectus (la˘tЉro¯-de˘kЈtu˘s) [L. latro, inherited as an autosomal recessive robber, ϩ Gr. daknein, biting] A ge- trait. nus of black spiders belonging to the lavage (la˘-va˘zhЈ) [Fr. lavage, a washing] family Theridiidae. Washing out of a cavity. SYN: irriga- L. mactans Black widow spider. tion. LATS long-acting thyroid stimulator. bronchoalveolar l. The removal of lattice (la˘tЈı˘s) 1. A network or frame- secretions, cells, and protein from the work formed by structures intertwined lower respiratory tract by insertion of usually at right angles with each other. sterile saline solution into the airways 2. In physics, the arrangement of atoms through a fiberoptic bronchoscope or a in a crystal. blindly inserted catheter. The fluid may lattice degeneration Atrophy or thinning be used to treat cystic fibrosis, pulmo- of the retina at its margins, a common nary alveolar proteinosis, or bronchial condition that affects about 10% of the obstruction due to mucus plugging, or to population. The condition is usually bi- obtain specimens for diagnostic pur- lateral and is often asymptomatic, al- poses. SYN: bronchopulmonary l. though affected persons may complain bronchopulmonary l. Bronchoalveo- of seeing sudden flashes of light. It is an lar lavage. occasional cause of retinal detachment. ductal l. The injection of a small laudable (lawdЈa˘-bı˘l) [L. laudabilis, amount of saline into the ducts of the praiseworthy] Commendable; healthy; breast through a miniature catheter, normal; formerly said erroneously of followed by collection of the fluid and pus. the cells that wash out with it. The cells laugh (la˘f) [ME. laughen, to laugh] are analyzed for evidence of early 1. The sound produced by laughing. changes that may suggest an increased SYN: risus. 2. To express emotion, usu- risk of future cancers. Occasionally they ally happiness or mirth, by a series of may reveal an already established can- inarticulate sounds. Typically the cer. mouth is open and a wide smile is gastric l. Rinsing or irrigating the present. stomach to remove or dilute irritants or sardonic l. Risus sardonicus. poisons or to cleanse the organ before or laughing gas Nitrous oxide. after surgery. Gastric lavage is used laughter (la˘fЈte˘r) A series of inarticulate most often to manage patients who have sounds produced as an expression of ingested potentially toxic medications, emotion, usually happiness or mirth. street drugs, hydrocarbons, or other The role of humor and laughter in pro- noncorrosive poisons. Its use in over- moting a positive attitude and health dose is controversial. Effectiveness de- and in preventing the progress of some pends on absorption speed and the time diseases has been documented esp. between ingestion and removal. It has when it is combined with proven medi- not been shown to improve clinical out- cal therapies. comes, except perhaps in those in- compulsive l. Laughter without stances in which the patient presents cause, occurring in certain psychoses, for care within an hour of a toxic inges- esp. schizophrenia. tion and the patient has consumed a pathological l. Uncontrolled laugh- life-threatening amount of poison. The ter (occasionally accompanied by, or al- procedure has some risks: the trachea, ternating with, uncontrolled crying), instead of the stomach, may be intu- caused by pseudobulbar lesions of the bated; gastric contents may be aspi- brain. These lesions may result from la- rated; and the mouth, teeth, pharynx, or cunar strokes, multiple sclerosis, anoxic esophagus may be injured. “Stomach brain injury, and other forms of brain pumping” is the colloquial term for gas- injury. tric lavage. l. reflex Uncontrollable laughter re- PATIENT CARE: The following equip- sulting from tickling or the fear of tick- ment is assembled: plastic large-lumen ling. nasogastric tube; water-soluble lubri- laughter therapy Humor therapy. cant; disposable irrigation set with bulb launch The release of a new drug or med- syringe; adhesive tape or other device; ical device into broad clinical use, that clamp, safety pins, and rubber band; is, into the marketplace. gloves and stethoscope; tissues; glass of Laurence-Moon-Biedl syndrome (lawЈ- water with straw; emesis basin; con- re˘ns-moonЈbe¯Јde˘l) [John Zachariah tainer for aspirant; at least 500 to 1000 Laurence, Brit. ophthalmologist, 1829– ml of prescribed irrigating solution; and 1870; Robert C. Moon, U.S. ophthalmol- any specified antidote. ogist, 1844–1914; Arthur Biedl, Prague Physical restraints are applied only if endocrinologist, 1869–1933] The com- prescribed and required. The patient’s bination of girdle-type obesity, sexual clothing is removed and a hospital gown short underdevelopment, mental retardation, put on. If conscious and cooperative, the standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh lavage 1306 law base of rh

patient is placed in the high Fowler’s po- ing to the bulb syringe or irrigant con- sition (head elevated 80 to 90 degrees), tainer and the other to a drainage set. and the chest is covered with a water- The return line is clamped, and the so- impermeable bib or drape. If uncon- lution, usually 500 ml or more, instilled scious, the patient is positioned to pre- to distend the stomach and expose all vent aspiration of stomach contents; areas to the solution. The large volume suction equipment is provided, and the also dilutes harmful liquids and thins or airway is protected. dissolves other materials. The distance for tube insertion is The patient is monitored throughout measured by placing the tip of the tube for retching. If retching occurs, the flow at the tip of the patient’s nose and ex- is stopped, suction is applied to the bulb tending the tube to the ear lobe and syringe, or the drainage line is opened then to the xiphoid process. The length to remove some of the instilled fluid. of tubing that will remain outside the The stomach is then drained, and the patient after insertion is marked on the procedure repeated as necessary to tube. Nostril patency is checked and the cleanse and empty the stomach of harm- nostril with the least obstruction is se- ful materials and irrigant. Alternately, lected. While the patient or an assistant 150 to 200 ml may be removed and the holds the emesis basin, the nurse lubri- same amount added on an alternating cates the tip of the tube and inserts it. basis. The process is repeated until a to- A downward and backward motion aids tal of 1000 ml has been employed and passage through the back of the nose drained. An activated charcoal slurry is and down into the nasopharynx, thus then instilled as appropriate and pre- avoiding producing a gag reflex. The pa- scribed. tient is instructed to dry-swallow during A specimen of the aspirant is sent to this phase of passage. The tube should the laboratory for analysis as directed. not be forced. If obstruction is met, the The tube may remain in place, attached tube is removed, the patient permitted to intermittent low suction, or be re- to rest briefly, the tube relubricated, moved immediately after the procedure. and the procedure attempted again. If For removal, the tube is clamped se- the tube cannot be passed without trau- curely. Any securing devices are re- matizing the mucosa, the physician is moved, and the tube is rotated gently to notified. ensure that it is freely moveable and When the tube is in the nasopharynx, then gently but steadily pulled out of the patient is instructed to flex the neck the nose and coiled. The patient is slightly to bring the head forward. The handed tissues to wipe the eyes and sip of water (if permitted) is given to the blow the nose and is assisted with oral patient, and the patient is encouraged hygiene. A fresh gown or linens are pro- to swallow the tube. Rotating the tube vided as necessary. toward the opposite nostril often helps After the procedure, the tube and pre- direct toward the esophagus and away scribed suction are maintained as nec- from the trachea. Placing the nondomi- essary, drainage is documented, comfort nant hand on the nose to secure the measures (oral misting, anesthetic tube, the practitioner advances it with throat sprays) are provided, and the pa- the dominant hand as the patient swal- tient is assessed and treated for any lows. complications of lavage or of the toxic The back of the throat is periodically exposure. inspected for any evidence of coiled tub- peritoneal l. Irrigation of the perito- ing, esp. if the patient is gagging or un- neal cavity (e.g., to diagnose blunt ab- comfortable, or unconscious. When the dominal trauma; to diagnose, by obtain- tube has been passed, placement is ver- ing cytologic specimens, or treat tumors ified by aspirating gastric contents with of the peritoneum with chemotherapeu- the bulb syringe. The tube is then se- tic agents; and to treat peritonitis, as- cured to the nostrils with adhesive tape sist in evacuation of blood, fecal soilage, or another securing device according to and/or purulent secretions as in hem- protocol. orrhage or peritonitis). law [AS. laga, law] 1. A scientific state- ment that is found to apply to a class of Gastric lavage should never be per- natural occurrences. 2. A body of rules, formed on a patient who has in- regulations, and legal opinions of con- gested corrosive acids or alkalis. It also duct and action that are made by con- should never be performed on patients trolling authority and are legally bind- who cannot protect their own airways, un- ing. less they are already intubated. administrative l. Body of law in the form of decisions, rules, regulations, The irrigation fluid is instilled, and and orders created by administrative care is taken to prevent the entrance of agencies under the direction of the ex- air. A Y connector can be attached to the ecutive branch of the government used short nasogastric tube, with one tubing exit- to carry out the duties of such agencies. standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh law 1307 law base of rh

Regulations of nursing practice, for ex- Good Samaritan l. SEE: Good Sa- ample, are considered administrative maritan law. laws. Graham’s l. SEE: Graham’s law. all-or-none l. The weakest stimulus l. of Grotthus-Draper SEE: Grotthus- capable of producing a response pro- Draper, law of. duces the maximum contraction of car- Gudden’s l. SEE: Gudden’s law. diac and skeletal muscle cells, and the Haeckel’s l. Biogenetic law. maximal impulse transmission rate in Hellin’s l. [Dyonizy Hellin, Polish pa- neurons. thologist, 1867–1935] SEE: Hellin’s Avogadro’s l. SEE: Avogadro’s law. law. Baruch’s l. SEE: Baruch’s law. Henry’s l. [William Henry, Brit. Beer’s l. SEE: Beer’s law. chemist, 1774–1836] SEE: Henry’s Bell’s l. SEE: under Bell, Sir Charles. law. biogenetic l. Ontogeny recapitu- Hilton’s l. SEE: Hilton’s law. lates phylogeny (i.e., an individual in Hooke’s l. SEE: Hooke’s law. its development recapitulates stages in inverse-square l. A law stating that its evolutionary development). SYN: the intensity of radiation or light at any Haeckel’s l. distance is inversely proportional to the Boyle’s l. SEE: Boyle’s law. square of the distance between the ir- case l. Opinions or decisions made by radiated surface and a point source. the courts. Thus, a light with a certain intensity at Charles’ l. SEE: Charles’ law. a 4-ft distance will have only one-fourth cosine l. 1. A physical law that de- that intensity at 8 ft and would be four scribes the relationship between the times as intense at a 2-ft distance. sides and angles of any triangle. l. of Laplace [Pierre-Simon Laplace, 2. When applied to physical treatment Fr. scientist, 1749–1827] SEE: La- of the body, it describes the effective- place, law of. ness of radiant energy and the angle at l. of Magendie Bell’s law. which it strikes tissue. The maximum Marey’s l. SEE: Marey’s law. amount of energy transfer occurs when l. of mass action In any chemical re- the energy strikes tissue at a 90Њ angle. action, the law that states that the ratio As the angle changes, the effectiveness of the mathematical products of the con- of the energy is reduced by the multiple centrations of the products to the math- of the cosine of the angle: Effective en- ematical products of the concentrations ergy ϭ applied energy ϫ cosine of the of the reactants is constant at a given angle. temperature. l. of contiguity 1. A law stating that Mendel’s l.’s SEE: Mendel’s laws. if two ideas occur together, then the rec- l. of multiple proportions When two ollection of one will likely stimulate re- substances unite to form a series of call of the other. 2. A law stating that chemical compounds, the proportions in if combined stimuli precede contraction which they unite are simple multiples of of a muscle, then, when those stimuli are one another or of one common propor- repeated, the muscle will contract again. tion. SEE: Dalton’s law. Courvoisier’s l. SEE: Courvoisier’s Nysten’s l. SEE: Nysten’s law. law. Ohm’s l. [Georg S. Ohm, Ger. physi- criminal l. Area of the law rel. to vi- cist, 1789–1854] SEE: Ohm’s law. olations of statutes that pertain to pub- periodic l. The physical and chemical lic offenses or acts committed against properties of chemical elements are pe- the public. A health care provider e.g., riodic functions of atomic weight. A nat- can be prosecuted for criminal acts such ural classification of elements is made as assault and battery, fraud, and according to their atomic weight. When abuse. arranged in order of their atomic weight Dalton’s l. [John Dalton, Brit. chem- or atomic number, elements show reg- ist, 1766–1844] SEE: Dalton’s law. ular variations in most of their physical l. of definite proportions Two or and chemical properties. more elements when united to form a Poiseuille’s l. [Jean Marie Poiseuille, new substance do so in a constant and Fr. physiologist, 1799–1869] SEE: Poi- fixed proportion by weight. SEE: Dal- seuille’s law. ton’s law. Ql. As temperature decreases, chem- Fick’s l. SEE: under Fick, Adolf Eu- ical activity decreases. gen. l. of reciprocal proportions In chem- Frank-Starling l. SEE: under Star- istry, the proportions in which two ele- ling’s law. mentary bodies unite with a third one fraud and abuse l. A statute that reg- are simple multiples or simple fractions ulates the appropriateness of health of the proportions in which these two care provider behavior in billing prac- bodies unite with each other. tices, receipt of payments, and provision reciprocity l. Any milliamperage of medically necessary services. multiplied by an exposure time setting short Gay-Lussac’s l. Charles’ law. that gives the same milliamperage- standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh law 1308 layer base of rh

second outcome should give the same tinal walls, softening the bowel contents relative density to an image. However, by increasing the amount of water in the this law is dramatically affected by the intestines, and increasing the bulk of image receptor response curve, esp. the bowel contents. Many people feel when it is not a 45Њ linear curve. In ra- that it is essential to have one or more diographic intensifying film and screen bowel movements a day, and, if they do technologies, the reciprocity law does not, they may develop the habit of tak- not hold at long exposure times because ing some form of laxative daily. They of the reversal of the D log E response should be instructed that missing a curve. bowel movement is not harmful and right-to-know l. A law that dictates that bowel movements do not necessar- that employers must inform their em- ily occur at regular intervals. SYN: ape- ployees of the health effects and chem- rient; cathartic; purgative. SEE: consti- ical hazards of the toxic substances used pation; enema. in each workplace. The employer must l. regimen A diet modified to avoid provide information concerning the ge- chronic constipation by eating high- neric and chemical names of the sub- bulk foods that contain a high fiber con- stances used; the level at which the ex- tent, eating foods that tend to stimulate posure is hazardous; the effects of bowel activity (e.g., stewed fruits and exposure at hazardous levels; the symp- vegetables), maintaining adequate fluid toms of such effects; the potential for intake, and participating in regular ex- flammability, explosion, and reactivity ercise. of the substances; the appropriate emer- laxity (la˘kЈsı˘-te¯) [L. laxitas, openness] gency treatment; proper conditions for The amount a joint or ligament deviates safe use and exposure to the substances; from its initial position when a force is and procedures for cleanup of leaks and applied to it. spills. The law provides that an em- layer (la¯Јe˘r) [ME. leyer] A stratum; a ployee may refuse to work with a toxic thin sheetlike structure of more or less substance until he or she has received uniform thickness. information concerning its potential for ameloblastic l. The enamel layer of hazard. SEE: hazardous material; the tooth. SYN: enamel l. health hazard; material safety data bacillary l. The rod and cone layer of sheet; permissible exposure limits. the retina of the eye. Rubner’s l.’s SEE: Rubner’s laws. basal l. The outermost layer of the Starling’s l. [Ernest Henry Starling, uterine endometrium lying next to the Brit. physiologist, 1866–1927] SEE: myometrium. SYN: basilar l. Starling’s law. basilar l. Basal layer. Stoke’s l. [William Stokes] SEE: Bernard’s glandular L. SEE: Ber- Stoke’s law. nard’s glandular layer. Sutton’s l. SEE: Sutton’s law. choriocapillary l. Lamina choriocap- Waller’s l. of degeneration SEE: illaris. Waller’s law of degeneration. clear l. The stratum lucidum of the Weber’s l. SEE: Weber’s law. epidermis. Weigert’s l. [Carl Weigert, Ger. pa- columnar l. A layer of tall, narrow thologist, 1845–1904] SEE: Weigert’s epithelial cells forming a covering or lin- law. ing. Wolff’s l. SEE: Wolff’s law. compact l. The compact surface law of effect The psychological principle layer of the uterine endometrium. that positively reinforced behaviors will cuticular l. of epithelium A layer of be repeated and negatively reinforced dense cytoplasm at the luminal end of behaviors will diminish or be extin- some epithelial cells, esp. that at the guished. surface of columnar epithelium of the lawn A layer of microorganisms growing intestine. on a culture medium. enamel l. Ameloblastic layer. lawrencium (la˘-re˘nЈse¯-u˘ m) [Ernest O. ependymal l. The inner layer of cells Lawrence, U.S. physicist, 1901–1958] of the embryonic neural tube. SYMB: Lr. A synthetic transuranic epitrichial l. Epitrichium. chemical element; atomic weight of the functional l. The portion of the en- most stable isotope is 260; atomic num- dometrium adjacent to the uterine cav- ber is 103. ity; after it is shed in menstruation it is lax (la˘ks) [L. laxus, slack] 1. Without regenerated by the basilar layer. tension. 2. Loose and not easily con- ganglionic l. 1. The fifth layer of the trolled; said of bowel movements. cerebral cortex. 2. The inner layer of laxative (la˘kЈsa˘-tı˘v) [L. laxare, to loosen] ganglion cells in the retina whose axons A food or chemical substance that acts form the fibers of the optic nerve. to loosen the bowels and prevent or germ l. One of the three primary lay- treat constipation. Laxatives may act by ers of the developing embryo from which increasing peristalsis by irritating the the various organ systems develop. short intestinal mucosa, lubricating the intes- SEE: ectoderm; endoderm; mesoderm. standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh layer 1309 lead base of rh

germinative l. The innermost layer of uterine glands. SYN: stratum spon- of the epidermis, consisting of a basal giosum. layer of cells and a layer of prickle cells subendocardial l. The layer of loose (stratum spinosum). SYN: malpighian connective tissue between the endocar- layer; stratum germinativum. dium and the myocardium. granular exterior l. The second layer subendothelial l. The layer of fine fi- of the cerebral cortex, consisting of py- bers and fibroblasts lying immediately ramidal cells. under the endothelium of the tunica in- granular interior l. The fourth layer tima of larger arteries and veins. of the cerebral cortex, consisting prin- Tomes’ granular l. The layer of in- cipally of closely packed stellate cells. terglobular dentin beneath the dentin- half-value l. ABBR: HVL. The ocemental junction in the root of a tooth. amount of lead, copper, cement, or other Weil’s basal l. A relatively cell-free material that would dissipate a beam of zone just below the odontoblastic layer radiation by 50%. The number of half- in the dental pulp. It is also called su- value layers required for safety in block- bodontoblastic layer; cell-free zone of ing the area on a patient is five, because Weil; cell-poor zone. that represents 50% of 50% and 50% of Lazarus sign (la˘zЈa˘r-u˘ssı¯n) [Biblical fig- that, and so forth. For example, 50% ϩ ure in the New Testament] Dramatic 25% ϩ 12.5% ϩ 6.23% ϩ 3.12% ϭ movements of the arms across the torso, 96.9%. Thus the patient would be which are occasionally observed in shielded from all but about 3% of the ra- brain-dead patients after they have diation. (Examples of the thickness of been disconnected from mechanical life material required to protect from radi- support. These movements may be mis- ation are 2 in [5 cm] of lead or 2 ft [61 interpreted as signs of life, when in fact cm] of cement.) they are merely involuntary reflexes. Henle’s l. SEE: Henle’s layer. lb pound. horny l. Outermost layer of the skin, LBBB left bundle branch block. consisting of clear, dead, scalelike cells, LC50 [Fm. lethal concentration] An ab- those of the surface layer being con- breviation for the concentration of a stantly desquamated. SYN: stratum toxin that will kill 50% of organisms ex- corneum. posed to it. Huxley’s l. SEE: Huxley’s layer. LD lethal dose. mantle l. The middle layer of the LD50 The median lethal dose of a sub- neural tube of the developing embryo. stance, which will kill 50% of the ani- molecular l. 1. The outermost layer mals receiving that dose. Dose is usu- of the cerebral or cerebellar cortex. ally calculated on amount of material 2. The inner or outer plexiform layer of given per gram or kilogram of body weight or amount per unit of body sur- the retina. face area. odontoblastic l. The layer of connec- LDB-CPR load-distributing band cardio- tive tissue cells at the outer edge of the pulmonary resuscitation. pulp where they produce the dentin of LDH lactic dehydrogenase. the tooth. LDL low-density lipoprotein. osteogenic l. The inner layer of the L-dopa L-3,4-dihydroxyphenylalanine; a periosteum; it contains osteoblasts that drug used in the treatment of Parkin- become active during repair of frac- son’s disease. SYN: levodopa. tures. SYN: Ollier layer. LDRP An acronym for Labor, Delivery, papillary l. The superficial layer of Recovery, Postpartum that describes a the corium lying immediately under the maternity unit designed for family-cen- epidermis into which it extends, form- tered care. Women in labor and their ing dermal papillae. families complete normal childbearing pigment l. The outermost layer of experiences in one homelike room. The the retina. Cells contain a pigment newborn may remain at the bedside called fuscin. thoughout the stay. prickle cell l. Stratum spinosum ep- LE lupus erythematosus. idermidis; the layer between the gran- leachate (le¯chЈa¯t) 1. A contaminated liq- ular and basal layers of the skin. Prickle uid that leaves soil after water perco- cells are present in this layer. SYN: spi- lates through earth (e.g., in waste dis- nous l. posal sites), farmlots, or landfills. 2. Any Purkinje l. SEE: Purkinje layer. product of percolation. reticular l. The inner layer of the co- leaching (le¯chЈı˘ng) [AS. leccan, to wet] rium lying beneath the papillary layer. Extraction of a substance from a mix- l. of rods and cones The layer of the ture by washing the mixture with a sol- retina of the eye next to the pigment vent in which only the desired sub- layer. It contains the rods and cones. stance is soluble. SYN: lixiviation. spinous l. Prickle cell layer. lead (le¯d) [AS. laedan, to guide] 1. In- spongy l. Middle layer of the uterine sulated wires connecting a monitoring short endometrium; contains dilated portions device to a patient. 2. A conductor at- standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh lead 1310 learning base of rh

tached to an electrocardiograph. The dantoin, or diazepam. Hydration should three limb leads are lead I, right arm to be maintained with intravenous admin- left arm; lead II, right arm to left leg; istration of fluids, while avoiding so- lead III, left arm to left leg. These are dium-containing materials. Oral fluids also known as standard leads, bipolar or food should not be given for at least limb leads, or indirect leads. SEE: elec- 3 days. trocardiogram for illus. l. line SEE: line, lead. bipolar l. In electrocardiography, any l. monoxide A reddish-brown com- lead that consists of one electrode at one pound used to prepare lead subacetate. body site and another at a different site. l. pipe contraction Cataleptic condi- A standard limb lead, I, II, or III, is a tion during which limbs remain in any bipolar lead. position in which placed. esophageal l. A lead that is placed in leading zero A zero that precedes a dec- the esophagus. imal point, e.g., as in “levothyroxine 0.5 limb l. Any lead, unipolar or bipolar, mg p.o. daily.” Leading zeros should al- in which a limb is the location of one of ways be employed when writing pre- the electrodes. scriptions for doses of drugs that are precordial l. A lead having one elec- fractions of a unit. In the example above trode placed over the precordium, the an alternative method of writing the other over an indifferent region. drug dose without decimals is “levothy- unipolar l. In electrocardiography, roxine 50 ␮g p.o. daily.” any lead that consists of one electrode lead molecule (le¯d) A chemical com- placed on the chest wall overlying the pound thought to be useful, safe, and heart, where potential changes are of distinctive enough that it might prove to considerable magnitude, and the other be a good candidate for drug develop- (distant or indifferent electrode) placed ment. in a site where potential changes are of lead optimization (le¯d) The synthetic re- small magnitude. finement of a candidate drug from its lead (le˘d) [L. plumbum] SYMB: Pb. A crude or original state into an agent metallic element whose compounds are that is safer, more useful, or more mar- poisonous; atomic weight 207.2, atomic ketable. number 82, specific gravity 11.35. Ac- lead poisoning SEE: under poisoning. cumulation and toxicity occur if more leaflet The part of a valve designed to than 0.5 mg/day is absorbed. Any level open in the direction of flow and close to of lead in the blood is abnormal. Most prevent backflow. Its base is typically cases of lead poisoning occur in children attached to a larger structure by a fixed who live in homes in which the paint stalk and its unattached end moves. contains lead. Children who eat the leakage current In electrosurgery cur- paint develop signs of lead toxicity. rent that flows toward a ground along a SEE: acute l. encephalopathy; lead poi- path that the surgeon did not intend. soning, acute; lead poisoning, chronic; lean (le¯n) [AS. hlaene, without flesh] pica. Without excess fat; as applied by the l. acetate A lead compound that is USDA it indicates that a meat or poul- used in solution as an astringent. try product contains less than 10 g of acute l. encephalopathy A syndrome fat, 4.5 g of saturated fat and 95 mg of seen mostly in children, following the cholesterol per serving. rapid absorption of a large amount of l. body mass The weight of the body lead. Initially there is clumsiness, ver- minus the fat content. It includes bones, tigo, ataxia, headache, insomnia, rest- muscles, and internal organs. lessness, and irritability. As the syn- Leapfrog Group An initiative driven by drome progresses, vomiting, agitation, Fortune 500 companies and other large confusion, convulsions, and coma will private and public health care purchas- occur. A sudden and marked increase in ers working to initiate breakthrough intracranial pressure accompanies improvements in the safety, quality, these symptoms. Sequelae include per- and affordability of health care through manent damage to the central nervous technology. system, causing mental retardation, learned nonuse Behavior sometimes ob- electroencephalogram abnormalities, served in patients with hemiparesis in cerebral palsy, and optic atrophy. whom functional use of the paralyzed TREATMENT: Lead exposure should arm is avoided after unsuccessful at- be discontinued. Corticosteroids and in- tempts to use it. This phenomenon may travenous mannitol, 20% solution, will represent a special application of relieve increased intracranial pressure. learned helplessness. Lead can be removed from the body by learning A change in behavior or skill ac- giving dimercaprol (BAL) and calcium quired by experience and practice. disodium edetate in a carefully admin- asynchronous l. A method of instruc- istered dose schedule. Convulsions may tion in which students access course short be controlled with phenobarbital, hy- material and engage with instructors standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh learning 1311 lecithin : sphingomyelin ratio base of rh

and other students from geographically intercept, and correlation coefficient are disparate locations or at different times. also usually calculated. Once this is Techniques in asynchronous learning done, various statistical and analytical include on-line chats, threaded discus- inferences can be made, so that the sions, or self-directed learning modules. quality of the analytical process can be Before the world wide web, asynchro- assessed. nous learning was called correspon- leave, leave day, therapeutic leave day A dence education. planned and supervised furlough from explicit l. Learning that results from care, esp. from a residential care facil- clearly stated directions or instructions. ity. Leaves are often granted so that res- implicit l. Learning that takes place idents of a care facility can spend time without directions or deliberate instruc- with their family. Leave days may also tion. be required from time to time when res- interactive l. Learning in which stu- idents need specialized services or in- dents receive feedback for their educa- patient medical care. tional efforts, usually from other stu- Leber’s disease, Leber’s hereditary optic dents, teachers, mentors, or electronic neuropathy (la¯Јbe˘rz) [Theodor Leber, educational resources. Ger. ophthalmologist, 1840–1917] Bi- latent l. Learning that is inapparent lateral blindness inherited from mater- to the individual at the time it occurs, nal mitochondria. It primarily affects only to become evident later. males. lifelong l. Learning that continues Leber’s plexus A plexus of venules in the after formal education ends and fosters eye between Schlemm’s canal and Fon- professional, intellectual, aesthetic, so- tana’s spaces. cial, and leadership skills. Leboyer method (le˘-boy-ya¯Ј) [Frederick motor l. The processes related to the Leboyer, Fr. obstetrician, b. 1918] An acquisition and retention of skills asso- approach to childbirth that employs a ciated with movement. They are influ- darkened, quiet, and peaceful environ- enced by practice, experience, and mem- ment. Central to this method is the ory. physical contact between the mother programmed l. An interactive sys- and the child immediately after deliv- tem of education in which information ery. The newborn is supported in a is presented in small increments. As warm bath at this time. Caressing and each new fact or concept is introduced, massaging the infant begins immedi- the student is required to use what he ately and is continued daily for several has learned by responding to a pre- months. The method is believed to facil- scribed series of questions. Mastery of itate the child’s mental and physical de- each topic must be demonstrated before velopment. the student can proceed to more ad- lecithal (le˘sЈı˘-tha˘l) [Gr. lekithos, egg vanced subject matter. SEE: Skinner yolk] Concerning the yolk of an egg. box. lecithin (le˘sЈı˘th-ı˘n) [Gr. lekithos, egg synchronous l. Multi-site learning yolk] A phospholipid (phosphoglycer- (distance education) in which learners ide) that is part of cell membranes; also are linked to their instructor(s) by chat found in blood, egg yolk, and soybeans. and audio conferencing software so that On hydrolysis, it yields stearic acid, they can ask questions and receive feed- glycerol, phosphoric acid, and choline on back in real time. hydrolysis. SYN: phosphatidycholine. learning disorder One of a variety of dis- lecithinase (le˘sЈı˘-thı˘n-a¯s) An enzyme orders characterized by difficulty read- that catalyzes the decomposition of lec- ing, writing, or using mathematical ithin. symbols that is two standard deviations cobra l. An enzyme present in cer- below the norm for one’s age and other- tain snake venoms. wise normal intelligence. The condition lecithin : sphingomyelin ratio (le˘sЈı˘-thı˘n may become apparent at an early age sfı˘ngЉgo¯-mı¯Јa˘-lı˘n ra¯Јshe¯-o¯) ABBR: L : S but usually is not recognized until the ratio. The ratio of lecithin to sphingo- child begins formal education in school. myelin in the amniotic fluid. It is used The frequency of this condition in boys to assess maturity of the fetal lung. Un- is five times that in girls. About 5% of til about the 34th week of gestation, the children in school use special educa- lungs produce less lecithin than sphin- tional services because of learning dis- gomyelin. As the fetal lungs begin to orders. mature, they produce more lecithin LEAS lower extremity arterial studies. than sphingomyelin. Delivery before the SEE: ankle-brachial index. reversal of the ratio is associated with least squares analysis A technique for an increased risk of hyaline membrane statistical assessment of data that min- disease in the infant. The use of this test imizes the sum of the squares of the dis- enables the obstetrician to determine tances from each data point to a line or the best time for elective termination of short plane. As part of the process, the slope, pregnancy. Other tests commonly used standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh lecithoblast 1312 Legionnaires’ disease base of rh

for this purpose include the amniotic la- knee to ankle, the tibia and fibula. SEE: mellar body count, phosphatidylglycerol illus. presence, and the shake test. SEE: am- bandy l. Bowleg. niocentesis. bayonet l. An uncorrected posterior lecithoblast (le˘sЈı˘-tho¯-bla˘stЉ)[Љϩblas- displacement of the knee bones, fol- tos, germ] One of the cells that prolif- lowed by ankylosis at the joint. erates to form the yolk sac. milk l. Phlegmasia alba dolens. lecithoprotein (le˘sЉı˘-tho¯-pro¯Јte¯-ı˘n) [Љϩ restless l. SEE: restless legs syn- protos, first] A protein in which lecithin drome. is part of the conjugate. scissor l. Crossed-leg deformity, a re- lectin (le˘kЈtı˘n) [L. legere, to pick and sult of double hip disease, in which the choose] One of several plant proteins patient walks with the legs swinging that stimulate lymphocytes to prolifer- across the midline with each step. ate. Phytohemagglutinin and concana- white l. Phlegmasia alba dolens. valin A are lectins. SEE: mitogen. legal Pert. to or according to the law. lectual (le˘ktЈu¯-a˘l) [L. lectus, bed] Con- legally mandated treatment Compulsory fining to a bed or couch, said of certain treatment; i.e., treatment that is de- diseases. manded by the courts. Usually, patients LED light-emitting diode. who are commanded to receive particu- leech (le¯tch) [AS. laece] A bloodsucking lar forms of treatment are prisoners, water worm, belonging to the phylum probationers, mentally ill individuals, Annelida, class Hirudinea. It is para- people with certain communicable dis- sitic on humans and other animals. eases (e.g., tuberculosis), or persons Leeches were used as a means of blood- with a history of substance abuse. letting, a practice common up to the Legg-Calve´-Perthes disease, Legg’s dis- middle of the 19th century but now al- ease (le˘gЈka˘l-va¯Јpe˘rЈte˘z) [Arthur T. most completely abandoned. The worms Legg, U.S. surgeon, 1874–1939; are a source of hirudin, an anticoagu- Jacques Calve´, Fr. orthopedist, 1875– lant secreted by their buccal glands. In 1954; Georg C. Perthes, Ger. surgeon, modern medicine leeches are used to 1869–1927] Osteochondritis (disinte- evacuate periorbital hemorrhage (black gration) of the proximal femoral epiph- eye) and to remove congested venous ysis, a condition usually found in boys blood from the suture lines of reim- between 5 and 10. SYN: coxa plana. planted fingers. In addition to hirudin, leggings (le˘gЈgı˘ngs) [ME. leg, leg] leech saliva contains several active sub- Stockings or dressings applied to the stances including inhibitors of platelet lower extremities, e.g., to provide com- aggregation, that have been synthe- pression or support. sized for use as anticoagulants in clot- Legionella (le¯Љjı˘-ne˘lЈa˘) [NL., from “Le- ting disorders. SEE: Hirudinea; hirudi- gionnaire’s disease”] A genus of gram- niasis. negative, motile, aerobic bacilli of the artificial l. Cup and suction pump or family Legionellaceae. They are found syringe for drawing blood. in natural water and may contaminate Lee’s ganglion (le¯z) [Robert Lee, Brit. water used for human consumption, air- gynecologist and obstetrician, 1793– conditioning, or waste disposal. 1877] Cervical uterine ganglion formed L. longbeachae A species that causes from the third and fourth sacral nerves sporadic cases of pneumonia and infec- and the hypogastric and ovarian plex- tions in immunocompromised hosts. uses. L. pneumophila (le¯-ju˘n-Љe˘l-la˘) The LEEP loop electrosurgical excision proce- species that is the usual cause of Le- dure. gionnaires’ disease and Pontiac fever. Leeuwenhoek’s disease (lu¯ Јe˘n-ho¯ks) SEE: Legionnaires’ disease. [Antoni van Leeuwenhoek, Dutch mi- legionellosis (le¯Љju˘-ne˘-lo¯Јsı˘s) Legion- croscopist, 1632–1723] Repetitive in- naires’ disease. voluntary contractions (“fluttering”) of Legionnaires’ disease (le¯-ju˘-ne˘rzЈ) [after the diaphragm and accessory muscles of Legionnaires stricken while attending respiration. The patient may experience an American Legion convention in Phil- shortness of breath and epigastric pul- adelphia, PA, in 1976] A severe, some- sations. The disease is caused by an times fatal disease characterized by abnormality of the respiratory control pneumonia, dry cough, myalgia, and system of the brainstem. SYN: dia- sometimes gastrointestinal symptoms. phragmatic flutter; respiratory my- It may occur in epidemics or sporadi- oclonus. cally and is an important cause of noso- left The opposite of right. SYN: sinistral. comial pneumonia because health-care left-handedness Using the left hand as associated legionellosis, while rare, is the dominant hand, e.g., for writing, more likely to be fatal than legionellosis work, or sports. SYN: sinistrality. acquired in the community at large. Ap- leg (le˘g) [ME.] In common usage, the prox. 8,000 – 18,000 people are infected entire lower limb, or from hip to ankle; each year in the U.S. Persons at risk in- short anatomically, only the lower leg, from clude middle-aged or older adults who standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh Legionnaires’ disease 1313 Legionnaires’ disease base of rh

ILIOPSOAS

GLUTEUS PECTINEUS MAXIMUS

ADDUCTOR SARTORIUS LONGUS

ADDUCTOR MAGNUS RECTUS FEMORIS GRACILIS BICEPS FEMORIS VASTUS VASTUS LATERALIS LATERALIS

SEMITENDINOSUS

VASTUS MEDIALIS

SEMIMEMBRANOSUS

PLANTARIS

PERONEUS LONGUS GASTROCNEMIUS

TIBIALIS ANTERIOR

EXTENSOR DIGITORUM SOLEUS PERONEUS LONGUS LONGUS FLEXOR DIGITORUM LONGUS EXTENSOR HALLUCIS LONGUS PERONEUS BREVIS

EXTENSOR EXTENSOR DIGITORUM BREVIS HALLUCIS BREVIS

MUSCLES OF THE LEG

smoke cigarettes or have chronic lung indoor waterfalls) or contaminated res- disease and those whose immune sys- piratory therapy equipment or nasogas- tems are compromised by diabetes, re- tric tubes. It thrives at temperatures nal failure, organ transplantation, can- about 90Њ–105ЊF (32Њ–41ЊC). Two dis- cer, or AIDS. The disease is responsible tinct diseases occur from the various Le- for about 5% of all pneumonias. SYN: gionella species: Legionnaires’ disease legionellosis. or a milder influenza-like illness known ETIOLOGY: The infection is caused as Pontiac fever. by bacteria of the genus Legionella. The SYMPTOMS: The signs and symp- bacteria may be inhaled or aspirated toms of Legionnaire’s disease are simi- from contaminated water supplies (e.g., lar to those of other pneumonias. Fa- water cooling towers, humidifiers, air tigue, anorexia, headache, malaise, conditioning vents, hot water tanks, myalgia, and diarrhea also may be whirlpools, spas, showers, hydrother- present. The incubation period is 2 to 10 short apy tanks, public water fountains, and days. standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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pulse oximetry readings, hydration, and color of lips and mucous membranes are also monitored. The health care pro- vider should be alert for signs of shock ACETABULUM PUBIS and monitor for complications such as HEAD respiratory failure. Level of conscious- ness is monitored for signs of neuro- ISCHIUM GREATER TROCHANTER logical deterioration, and seizure precautions are instituted as needed. Prescribed antibiotic therapy is admin- NECK istered and evaluated for desired effects LESSER and adverse reactions. Respiratory care TROCHANTER is provided, including prescribed oxygen therapy, repositioning, postural drain- FEMUR age, chest physiotherapy, and suction- ing as prescribed and warranted by the patient’s condition. If it is required, the respiratory therapist assists with en- PATELLA dotracheal intubation and the provision MEDIAL and management of mechanical venti- CONDYLE LATERAL CONDYLE lation or other prescribed respiratory MEDIAL therapies. Antipyretics are adminis- CONDYLE LATERAL tered and tepid sponge baths given. A CONDYLE TIBIAL cooling blanket may be used as pre- TUBEROSITY scribed to control fever. Frequent oral HEAD TIBIA hygiene is provided, and a soothing cream is applied to irritated nostrils if FIBULA necessary. Fluid and electrolyte balance MEDIAL is monitored, and replacement therapy MALLEOLUS initiated as needed and prescribed. Pre- scribed antiemetics are administered if TALUS LATERAL MALLEOLUS needed. The respiratory therapist or NAVICULAR nurse teaches the patient about pulmo- nary hygiene, including the use of incen- CALCANEUS TARSALS CUNEIFORMS CUBOID tive spirometry. The patient is also FIRST taught methods to prevent disease METATARSALS SECOND transmission. THIRD The use of sterile water only (not dis- PHALANGES tilled or tap water) in respiratory ther- TARSALS apy equipment and other aerosolizing and misting devices helps prevent noso- BONES OF THE LEG AND FOOT comial Legionella infections. Legionella can survive for long periods in plumbing Anterior view systems by developing a biofilm, which forms on the inner surfaces of pipes and water tanks, provides a safe environ- DIAGNOSIS: It is diagnosed by cul- ment for the bacteria that is difficult to turing sputum or bronchial washings eradicate, and resists water disinfec- and growing the bacteria on a special tants. Disruption of the biofilm then medium and silver staining; the bacte- disperses the bacteria throughout the ria can also be identified by blood serol- system. If Legionella is found in a facil- ogy for antibody titer or by antigen test- ity’s water supply, the system can be ing of urine. cleansed by hyperchlorination or super- TREATMENT: Erythromycin given heating though recolonization may early in the course of the disease and for eventually occur. The Centers for Dis- a prolonged period is the treatment of ease Control and Prevention encourage choice. Rifampin may also be given as but do not require water testing, but an adjunct but should not be used alone. high-risk care centers should have a Other macrolides (e.g., clarithromycin testing strategy in place and should con- and azithromycin) and fluoroquinolones sider testing all patients with hospital- are effective therapeutic options. Peni- acquired pneumonia for Legionella in- cillin, cephalosporins, and aminoglyco- fections. Legionnaires’ infections may sides are ineffective. need to be reported to the health de- PATIENT CARE: Respiratory status partment, depending on state regula- is monitored, including chest wall ex- tions. SEE: pneumonia. pansion, depth and pattern of ventila- legitimate medical practice Any form of tions, cough and chest pain, and restless- treatment that is accepted under the ness, which may indicate hypoxemia. Medical Practice Acts enacted by each short Vital signs, arterial blood gas levels, of the fifty U.S. states. standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh leg lifter 1315 leishmaniasis base of rh leg lifter An assistive device used to move pedicles. Intraligamentous leiomyomas: the lower extremities from one place or grow in the broad ligament, with or surface to another; it typically consists without uterine attachment. Intramu- of a large loop attached to a manually ral leiomyomas: found within the mus- operated handle that encircles and lifts cle wall of the uterus, if large, can give the foot or thigh. It is used by people the uterus a nodular, irregular shape. who have difficulty moving their legs as Submucosal leiomyomas: excessive, of- a result of edema, joint disease, obesity, ten abnormal bleeding, abdominal stroke, or other disabilities. cramping, or pain are the most common legume (le˘Јgu¯m) [L. legumen, pulse, symptoms. Cervical Leiomyomas: may bean] Fruit or pod of beans, peas, or cause stress incontinence, polyuria, dys- lentils. parunia, or increased vaginal discharge. COMPOSITION: Legumes are a rich Many leiomyomas are asymptomatic. source of protein and essential amino TREATMENT: These tumors grow acids. They contain legumin, a globulin, only during the reproductive years, of- and significant quantities of dietary fi- ten regressing after menopause. Surgi- ber, iron, and calcium. cal treatment (myomectomy or hyster- VITAMINS: Sprouted beans are a ectomy) may be necessary if tumors are good source of vitamin B complex. Vi- more than 20 weeks, gestational size. tamin A and ascorbic acid are present in Some tumors may be removed lapros- small amounts. copically, although submucous tumors CARBOHYDRATES: Carbohydrate is are removed by dilatation and curettage present in the form of starch in about (D&C) or by hysteroscopy. Gonadotro- the same proportion as in the cereals phin-releasing hormones (GnRH) cause but with more cellulose. suppression of ovarian hormones and Ј legumin (le˘-gu¯ mı˘n) [L. legumen, pulse, may cause tumors to shrink. SYN: fi- bean] An albumin present in many le- broid tumor; fibroids of uterus; myoma guminous seeds. SEE: legume. uteri; uterine fibroma. Ј Leiner’s disease (lı¯ ne˘rz) [Karl Leiner, leiomyosarcoma (lı¯Љo¯-mı¯Љo¯-sa˘r-ko¯Јma˘) [Љ Austrian pediatrician, 1871–1930] Ex- ϩЉϩsarx, flesh, ϩ oma, tumor] A foliative dermatitis. Ј combined leiomyoma and sarcoma. Leininger, Madeleine (lı¯n ı˘ng-e˘r) The leiotrichous (lı¯-o˘tЈrı˘-ku˘s) [Љϩthrix, founder and leader of transcultural hair] Possessing smooth or straight nursing who developed the Theory of hair. Cultural Care Diversity and Universal- Leishman-Donovan bodies (le¯shЈma˘n- ity. SEE: Nursing Theory Appendix. do˘n-a˘-va˘n) [Sir William Boog Leish- leio- [L. leios, smooth] Combining form man, Brit. medical officer, 1865–1926; meaning smooth. Charles Donovan, Brit. bacteriologist, leiodermia (lı¯Љo¯-de˘rЈme¯-a˘) [Gr. leios, 1863–1951] Nonflagellated trypano- smooth, ϩ derma, skin] Dermatitis somes found within the cytoplasm of characterized by abnormal glossiness cells infected by Leishmania donovani, and smoothness of the skin. the pathogen that causes visceral Leish- leiomyofibroma (lı¯Љo¯-mı¯Љo¯-fı¯-bro¯Јma˘) [Љ ϩ ϩ ϩ maniasis. SYN: amastigote. mys, muscle, L. fibra, fiber, Ј Gr. oma, tumor] A benign tumor com- Leishmania (le¯sh-ma¯ ne¯-a˘) A genus of posed principally of smooth muscle and parasitic, flagellated protozoa that fibrous connective tissue. cause a variety of infectious diseases in leiomyoma (lı¯Љo¯-mı¯-o¯Јma˘) [ЉϩЉϩ humans. These tropical organisms are oma, tumor] A benign tumor consisting usually transmitted to people by the principally of smooth muscle. bite of the female sandflies, although epithelioid l. A smooth muscle tu- they may occasionally be transferred mor, usually of the stomach. from person-to-person by transfusion. uterine l. A benign tumor of the L. braziliensis The causative agent of uterus of smooth muscle origin. Also American leishmaniasis. called myoma, fibroid, or fibromyoma, it L. donovani The causative agent of is the most common tumor of the female kala azar (visceral leishmaniasis). reproductive tract. L. major A species of Leishmania SYMPTOMS: Many women with transmissible by rodents and causing leiomyomas have no symptoms, but skin infections in humans. Infection these growths may sometimes cause ab- with L. major is found principally in the dominal or pelvic heaviness, abnormal Middle East, East Africa, and the Med- uterine bleeding, frequent urination, iterranean. dysparunia, or pain. L. tropica The causative agent of Ori- Leiomyomas are classified according ental sore (cutaneous leishmaniasis). to their location. Subserous leiomy- leishmaniasis (le¯shЉma˘-nı¯Јa˘-sı˘s) A group omas: arise from the peritoneal covering of related chronic parasitic diseases of of the uterus. They may be large or the skin, viscera, or mucous mem- small firm protuberances from the outer branes, caused by species of the genus short surface of the uterus or be attached by Leishmania, which are transmitted to standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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humans by the bite of tiny, infected fe- male sandflies, 30 different species of which thrive in both tropical and tem- perate regions and carry Leishmania. Leishmaniasis has been known to occur in epidemics but occurs mostly as an en- demic disease in Asia, Africa, Latin America, and the Middle East; U.S. mil- itary personnel may be infected during overseas operations. One type of leish- maniasis, kala azar, causes visceral in- fection and involves the mononuclear phagocytic system, causing inflamma- tion and fibrosis of the spleen and liver. It can be fatal if untreated. Mucosal MUCOCUTANEOUS LEISHMANIASIS leishmaniasis infection produces muti- Cutaneous lesion caused by L. Braziliensis lating lesions that destroy the mucosa, esp. in the larynx, anus, and vulva. In the two cutaneous forms of leishmania- comes a neurilemma cell. SEE: nerve fi- sis, multiple skin ulcers form on ex- ber. posed areas of the face, hands, arms, lemniscus (le˘m-nı˘sЈku˘s) pl. lemnisci and legs. While these are not painful or [Gr. lemniskos, a ribbon] A bundle of contagious, if left untreated they can sensory fibers (lateral or exterior and leave permanent, disfiguring scars. median or interior) in the medulla and Leishmania organisms infect and repro- pons. duce inside macrophages and are con- lemon [Persian limun, lemon] Fruit of trolled by T-cell–mediated response. the tree Citrus limon, containing citric The strength of the patient’s immune acid. Lemons contain enough vitamin C system determines the severity of the to prevent or treat scurvy. Lemon may disease. SEE: kala azar. be used in place of vinegar, spices, and PATIENT CARE: There is no vaccine aromatic substances by those who can- against Leishmania. To prevent infec- not use such items. tion during exposure to sandfly vectors, topical repellants containing 30% to Food faddists who drink large 35% N,N-diethyl-3-methylbenzamide quantities of lemon juice by sucking (DEET) should be applied to the skin, directly from the raw fruit may develop and permethrin should be used to im- erosion of the enamel of their teeth. pregnate clothing, uniforms, bed net- ting, and screened enclosures. These Lene`gre’s disease (Le-nehЈgres) [Jean measures also protect tourists, travel- Lene`gre, 20th century Fr. cardiologist, ers, and military personnel from infec- 1904–1972] Atrioventricular or intra- tions caused by other biting insects (e.g., ventricular conduction abnormalities malaria). resulting from fibrosis of the His-Pur- TREATMENT: Drugs used to treat kinje fibers of the heart. leishmaniasis include amphotericin B, length The measurement of the distance miltefosine, paromomycin, and sodium between two points. stibogluconate. basinasal l. The distance from the American l. Mucocutaneous l. basion of the foramen magnum of the cutaneous l. An ulcerating, chronic, skull to the center of the suture between nodular skin lesion prevalent in Asia the frontal and nasal bones. and the tropics and due to infection with crown-heel l. In the embryo, fetus, or Leishmania tropica. SYN: Aleppo boil; newborn, the distance from the crown of Oriental sore. the head to the heel. mucocutaneous l. A form of cutane- crown-rump l. In the embryo, fetus, ous leishmaniasis, involving principally or newborn, the distance from the crown the nasopharynx and mucocutaneous of the head to the apex of the buttocks. membranes, found in parts of Central The measurement can be used to esti- and South America. The causative or- mate gestational age. ganism is Leishmania braziliensis focal l. In optics, the distance from transmitted by sandflies, usually of the the lens to the point of focus of light rays genus Lutzomyia. SYN: American leish- passing through the lens. maniasis. SEE: illus. l. of stay The number of days be- tegumentary l. Leishmaniasis that tween admission and discharge from an involves the skin or mucous mem- inpatient care facility. branes. wave l. In the line of progression of visceral l. Kala azar. a wave, the distance from one point on lemmocyte (le˘mЈo¯-sı¯t) [Gr. lemma, the wave to the same point on the next short husk, ϩ kytos, cell] A cell that be- wave. The length of a wave determines standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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whether or not the wave is a visible in a capsule, and held in place just be- light, x-ray, gamma, or radio wave. hind the pupil by the suspensory liga- Lennox-Gastaut syndrome (le˘nЈno˘ks- ment. It consists principally of lens fi- ga˘s-to¯Ј) [Henri Gastaut, Fr. neuro- bers that at the periphery are soft, scientist, 1915–1995; W.G. Lennox, forming the cortex lentis, and in the cen- Am. neurologist, 1884–1960] A form of ter of harder consistency, forming the early childhood epilepsy marked by nucleus lentis. Beneath the capsule on atypical absence and tonic-clonic sei- the anterior surface is a thin layer of zures, slow-spike electroencephalo- cells, the lens epithelium. The shape is graphic waves, and a high incidence of changed by the ciliary muscle to focus mental retardation. light rays on the retina. lens (le˘nz) [L. lens, lentil] 1. A trans- cylindrical l. A segment of a cylinder parent refracting medium; usually parallel to its axis, used in correcting made of glass. 2. The crystalline lens of astigmatism. the eye. disposable contact l. A soft contact achromatic l. Lens that transmits lens worn for a week or two and then light without separating it into the col- discarded. ors of the visual spectrum. extended wear contact l. A contact anterior chamber intraocular l. lens made of materials that permit per- ABBR: ACIOL. SEE: intraocular l. meation of gas (i.e., oxygen) so that aplanatic l. A lens that corrects there is less chance for corneal irrita- spherical aberrations. tion. apochromatic l. A lens that corrects gas permeable l. ABBR: GP lens. A both spherical and chromatic aberra- contact lens that allows oxygen to pass tions. through it—enhancing eye health, lens biconcave l. A lens that has a con- durability, and comfort. Gas permeabil- cave surface on each side. SEE: bicon- ity derives from the incorporation of sil- cave for illus. icone in lens plastic. GP lenses are used biconvex l. A lens that has a convex to manage visual conditions such as surface on each side. SEE: biconcave for astigmatism, keratoconus, and presby- illus. opia. SYN: rigid gas permeable l. bifocal l. SEE: bifocal eyeglasses. hard contact l. A contact lens made bifocal contact l. A contact lens that of rigid translucent materials. contains two corrections in the same implanted l. Intraocular lens. lens. intraocular l. ABBR: IOL. An arti- concave spherical l. A lens formed of ficial lens made of acrylic or silicone; the prisms with their apices together, which lens may be placed posterior to the iris is, therefore, thin at the center and (PCIOL) or anterior to the iris (ACIOL). thick at the edge. This type of lens is Posterior chamber lens may be mono- used in myopia. focal or multifocal and can also correct contact l. A device made of various an astigmatic error. A lens is removed materials, either rigid or flexible, that because of abnormalities such as cata- fits over the cornea or part of the cornea racts. If the original lens capsule is to supplement or alter the refractive ability of the cornea or the lens of the present and an IOL is placed inside it, eye. Contact lenses of any type require the surgical procedure is called posterior special care with respect to storage chamber IOL implantation. If the cap- when they are not being worn, direc- sule has been removed in a previous tions for insertion and removal, and the surgical procedure, the IOL may be length of time they can be worn. The placed in front of the iris, directly adja- manufacturer’s or dispensing health cent to the cornea. This is called ante- care worker’s instructions should be rior chamber IOL implantation. In an- read and followed. Failure to do this other procedure, the IOL is implanted could result in serious eye diseases. behind the iris. Which method of IOL Wearing contact lenses while swimming implantation produces the best results is inadvisable. is being investigated. SYN: implanted l. convexo-concave l. A lens with a SEE: cataract. convex surface on one side and a con- multifocal l. An eyeglass lens whose cave surface on the opposite side. power to alter light rays varies from the convex spherical l. A lens formed of top to the bottom of the lens, permitting prisms with their bases together, which a smooth transition from one power lens is, therefore, thick at the center and to the other as one moves the eyes. This thin at the edge. This type of lens is used is in contrast to an eyeglass lens with in hyperopia. the usual two-component bifocal lens. corneal contact l. A type of contact oil immersion l. A special lens with lens that adheres to and covers only the oil placed between the lens and the ob- cornea. ject being visualized. This eliminates a crystalline l. A transparent colorless layer of air between the microscope slide short biconvex structure in the eye, enclosed and the lens, producing a clearer image standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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than would be the case if the oil were that has extreme anterior spherical not used. bulging. orthoscopic l. A lens that produces lentigo (le˘n-tı¯Јgo¯) pl. lentigines [L., no distortion of the periphery of the im- freckle] Freckle. age. l. maligna A pigmented lesion of the rigid gas permeable l. Gas perme- skin in which a large number of super- able lens. ficial, atypical melanocytes are found. posterior chamber intraocular l. SYN: Hutchinson’s freckle. ABBR: PCIOL. SEE: intraocular l. l. senilis Solar lentigo. soft contact l. A contact lens made of solar l. A flat brown spot usually ap- flexible, translucent materials. These pearing on sun-exposed skin, such as lenses are more comfortable, can be the face or the back of the hands. They worn longer, and are harder to displace are commonly found on the skin of el- than hard lenses, but there are disad- derly individuals. Although they are vantages. They may not provide the popularly referred to as “liver spots,” same degree of visual acuity as hard they are not caused by diseases of the lenses and they require more cleaning liver. SYN: lentigo senilis. SEE: illus. and disinfection. Tear production may be decreased, esp. in older patients. The soft lenses may need to be replaced every 6 to 18 months. Corneal infections can prevent further use of soft lenses, as well as causing permanent loss of vi- sion. spherical l. A lens in which all sur- faces are spherical. toric contact l. A contact lens with two separate curvatures. It can be used, for example, to correct simultaneously astigmatism and distance vision. trial l. Any lens used in testing the LENTIGO OF SUN-EXPOSED SKIN vision. trifocal l. A corrective eyeglass lens lentivirus (le˘nЉtı˘-vı¯Јru˘s) [L. lentus, slow] containing three segments: for near, in- A group of retroviruses that cause termediate, and distant vision. slowly developing diseases as a result of zoom l. A type of lens that can be ad- the gradual killing of lymphoid cells. justed to focus on near or distant ob- Human immunodeficiency virus (HIV), jects. the virus that causes acquired immu- lensectomy (le˘n-ze˘k’to¯-me¯) [L. lens, len- nodeficiency syndrome (AIDS), is in- til, ϩ Gr. ektome, excision] The sur- cluded in this group of viruses. gical removal of the lens of the eye. leontiasis (le¯Љo˘n-tı¯Јa˘-sı˘s) [Gr. leon, lion, SYN: lentectomy. ϩ −iasis, condition] Lionlike appear- lentectomy (le˘n-te˘kЈto¯-me¯) [L. lens, len- ance of the face seen in certain diseases, til, ϩ Gr. ektome, excision] Lensec- esp. lepromatous leprosy. SYN: facies tomy. leontina. lenticonus (le˘nЉtı˘-ko¯Јnu˘s) [Љϩconus, l. ossea Enlargement and distortion cone] Conical protrusion of the anterior of facial bones, giving one the appear- or posterior surface of the lens. ance of a lion. It can occur as a compli- lenticular (le˘n-tı˘kЈu¯-la˘r) [L. lenticularis, cation of hyperparathyroidism, Paget’s lentil] 1. Lens shaped. SYN: lentiform. disease, uremia, and other conditions. 2. Pert. to a lens. Leopold’s maneuver (le¯Јo¯-po¯ldz) [Chris- lenticulostriate (le˘n-tı˘kЉu¯-lo¯-strı¯Јa¯t) [Љ tian Gerhard Leopold, Ger. physician, ϩ striatus, streaked] Rel. to the lentic- 1846–1911] In obstetrics, the use of ular nucleus and corpus striatum of the four steps in palpating the uterus in or- basal ganglia. der to determine the position and pre- lenticulothalamic (le˘n-tı˘kЉu¯-lo¯-tha˘- sentation of the fetus. SEE: illus. la˘mЈı˘k) Pert. to the lenticular nucleus leper (le˘pЈe˘r) [Gr. lepros, scaly] A per- and the thalamus. son afflicted with leprosy. lentiform (le˘ntЈı˘-form) [L. lens, lentil, ϩ lepidic (le˘-pı˘dЈı˘k) [Gr. lepis, scale] Con- forma, shape] Lenticular (1). cerning scales, or a scaly covering. lentiginosis (le˘n-tı˘jЉı˘-no¯Јsı˘s) [L. lentigo, lepido- [Gr. lepis, scale] Combining form freckle, ϩ Gr. osis, condition] The meaning flakes or scales. presence of multiple lentigines. SEE: Lepidoptera (le˘pЉı˘-do˘pЈte˘r-a˘) [Љϩ lentigo. pteron, feather, wing] An order of the lentiginous (le˘n-tı˘jЈı˘n-u˘s) [L. lentigo, class Insecta that includes the butter- freckle] 1. Affected by lentigo. 2. Cov- flies, moths, and skippers; character- ered with very small dots. ized by scaly wings, sucking mouth lentiglobus (le˘nЉtı˘-glo¯Јbu˘s) [L. lens, len- parts, and complete metamorphosis. short til, ϩ globus, sphere] A lens of the eye lepidosis (le˘pЉı˘-do¯Јsı˘s) [Љϩosis, condi- standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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LEOPOLD’S MANEUVERS

tion] Any scaly or desquamating erup- fected persons, it may produce charac- tion such as pityriasis. teristic ring-shaped, nodular, or erosive lepothrix (le˘pЈo¯-thrı˘ks) [Љϩthrix, hair] skin changes, esp. on or near the face, A condition in which the shaft of the and sensory and motor dysfunction, esp. hair is encased in hardened, scaly, se- of the hands and feet. Approx. 700,000 baceous matter. people are infected each year world- lepra (le˘pЈra˘) [Gr. lepra, leprosy] A term wide; leprosy is endemic in India (the formerly used for leprosy. It is now used site of 70% of cases) and other tropical to indicate a reaction that occurs in lep- countries. It occasionally is reported in rosy patients consisting of aggravation the U.S., e.g., in Hawaii, where it was of lesions accompanied by fever and once endemic, and in the Gulf Coast malaise. It can occur in any form of lep- states, where it is carried by an animal rosy and may be prolonged. host, the nine-banded armadillo. SYN: l. alba A form of lepra in which the Hansen’s disease. SEE: granuloma. skin is anesthetic and white, associated The lepromatous (LL) form is charac- with different forms of paralysis. terized by skin lesions and symmetrical l. Arabum True or nodular leprosy. involvement of peripheral nerves with l. maculosa A form of lepra with pig- anesthesia, muscle weakness, and pa- mented cutaneous areas. ralysis. In this form, the lesions are lim- leprechaunism (le˘pЈre˘-ko˘nЉı˘zm) An au- ited to the cooler portions of the body tosomal recessive disease in which elfin such as skin, upper respiratory tract, features of the face are accompanied by and testes. In tuberculoid (TT) leprosy, retardation of physical and mental de- which is usually benign, the nerve le- velopment, a variety of endocrine dis- sions are asymmetrical and skin anes- orders, emaciation, and susceptibility to thesia is an early occurrence. Visceral infections. SYN: Donohue’s syndrome. involvement is not seen. leprid (le˘pЈrı˘d) [Gr. lepra, leprosy, ϩ ei- Lepromatous leprosy is much more dos, form, shape] A leprous cutaneous contagious than the tuberculoid form. lesion. In the latter, M. leprae are found in le- leprology (le˘p-ro˘lЈo¯-je¯) [Љϩlogos, sions only rarely except during reac- word, reason] The study of leprosy and tions. methods of treating it. Between the two major forms are bor- leproma (le˘p-ro¯Јma˘) [Љϩoma, tumor] derline (BB) and indeterminate leprosy. A cutaneous nodule or tubercle charac- In the borderline group, the clinical and teristic of leprosy. bacteriological features represent a lepromatous (le˘p-ro¯Јma˘-tu˘s) Concern- combination of the two principal types. ing lepromas. SEE: leprosy. In the indeterminate group, there are lepromin An extract derived from Myco- fewer skin lesions and bacteria are bacterium leprae, the organism that much less abundant in the lesions. In causes leprosy. It is injected under the many respects, this infection resembles skin, in a fashion similar to the injection tuberculosis and for many years was re- of purified protein derivative (PPD), to garded as incurable; this is no longer determine the degree of a patient’s im- considered to be valid. mune response to leprosy. PPD testing ETIOLOGY: The disease-producing is used to gauge the immune response bacterium, M. leprae, grows only at 32Њ of patients to tuberculosis. to 34ЊC, the temperature of skin. A nor- leprostatic (le˘pЉro¯-sta˘tЈı˘k) [Љϩstati- mal T cell response by the host produces kos, standing] 1. Inhibiting the growth tuberculoid leprosy, which can be trans- of Mycobacterium leprae. 2. An agent mitted by respiratory droplets. Once in- that inhibits the growth of M. leprae. haled, the organisms produce granulo- leprosy (le˘pЈro¯-se¯) [Gr. lepros, scaly] A mas in the lungs and move through the chronic infectious disease of the skin bloodstream to the skin. and peripheral nerves, caused by My- In contrast, lepromatous (anergic) short cobacterium leprae. In chronically in- leprosy occurs in persons who have an standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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abnormal T-lymphocyte response to the spite effective treatments for many organism. Transmission requires con- patients, the incidence of leprosy world- tact between material from a skin lesion wide has not diminished in recent years. and the blood of a recipient, which is PROGNOSIS: With proper therapy, reached through cuts on the skin. Ge- esp. if given at the earliest time possi- netic differences have been identified in ble, the outlook is favorable. those who develop the two forms of lep- leprotic (le˘p-ro˘tЈı˘k) [Gr. lepra, leprosy] rosy. Other intermediate or borderline Leprous. forms of the disease are well-known, leprous (le˘pЈru˘s) 1. Pert. to leprosy. such as borderline lepromatous, border- 2. Affected by leprosy. SYN: leprotic. line tuberculoid, and tuberculoid lep- -lepsy [Gr. −lepsia, seizure] Suffix mean- rosy. ing seizure. SYMPTOMS: In tuberculoid leprosy, leptin (le˘pЈtı˘n) A helical peptide hor- skin lesions initially are flat and red, mone produced by adipose tissue. Lep- but later become large, hard, irregular, tin acts on cells in the hypothalamus in and swollen, with pale depressed cen- response to increases in body fat storage ters. Granulomas infiltrate the periph- to suppress appetite and increase en- eral nerves, which gradually degener- ergy expenditure. It also contributes to ate, producing loss of feeling in the skin, the onset of puberty and to the secretion muscle atrophy, and contractures. Lep- of insulin by the pancreas. romatous leprosy produces large macu- lepto- [Gr. leptos, thin, fine, slim] A com- lar (flat), papular (raised), or nodular le- bining form meaning thin, fine, slight, sions without sensation on the skin, delicate. particularly on the face, hands, knees, leptocephalia (le˘pЉto¯-se˘-fa¯Јle¯-a˘) [Gr. lep- and feet. The eyes, mucosa of the upper tos, slender, ϩ kephale, head] Having airway, and testes also are commonly an abnormally vertically elongated, involved. The lesions contain large narrow skull. numbers of infected macrophages. In- leptocephalus (le˘pЉto¯-se˘fЈa˘-lu˘s) An in- fection of peripheral nerves causes loss dividual possessing an abnormally ver- of sensation and muscle atrophy. Non- tically elongated, narrow skull. protective antibodies are formed, which leptochromatic (le˘pЉto¯-kro¯-ma˘tЈ˘k)ı [Љϩ bind with bacterial antigens; the result- chromatin] Having a fine chromatin ing immune complexes may cause vas- network. culitis and glomerulonephritis. In all leptomeninges (le˘pЉto¯-me˘n-ı˘nЈje¯s) sing., patients with leprosy, loss of sensation leptomeninx [Љϩmeninx, mem- leads to inadvertent trauma and skin brane] The pia mater and arachnoid as ulcers; autoamputation may occur. The distinct from the dura mater. SYN: pia- disease has a slow course and rarely arachnoid. causes death. leptomeningitis (le˘pЉta˘-me˘n-ı˘n-jı¯tЈı˘s) [Љ DIAGNOSIS: Biopsy of a suspected ϩЉϩitis, inflammation] Meningitis skin lesion is used for diagnosis. The ba- in which infection, carcinoma, or inflam- cilli may not be present in tuberculoid mation involves only the pia mater and lesions. In vitro tests of the immunolog- arachnoid membranes of the brain, not ical response can be accomplished by the dura mater. SEE: meningitis. the lymphocyte transformation test and SYMPTOMS: Patients have an acute the leukocyte migration inhibition test. headache, pain in the back, spinal rigid- COMPLICATIONS: Bacterial skin in- ity, irritability, and drowsiness ending fections, ulcers, and traumatic ampu- in coma. SYN: piarachnitis. tation of fingers owing to anesthesia leptomeningopathy (le˘pЉto¯-me˘nЉ˘n-ı may occur. Tuberculosis is a much more go˘pЈa˘-the¯) [ЉϩЉϩpathos, disease] common complication in untreated A disease of the leptomeninges of the cases of lepromatous leprosy than in the brain. tuberculoid form. Amyloidosis may be leptomeninx (le˘pЉto¯-me˘nЈı˘nks) Sing. of the cause of death in advanced cases. leptomeninges. TREATMENT: Tuberculoid leprosy is leptonema (le˘pЉto¯-ne¯Јma˘) [Љϩnema, treated with multiple drug therapies, thread] The early stage of prophase in such as daily oral dapsone plus one dose meiosis. At this stage the chromatin of rifampin each month for 6 months. coils into visible filaments. SEE: cell di- Daily dapsone and clofazimine plus vision. monthly doses of rifampin for 24 months leptophonia (le˘pЉto¯-fo¯Јne¯-a˘) [Љϩ are required to treat lepromatous lep- phone, voice] Weakness of the voice. rosy. Directly observed therapy is rec- leptoprosopia (le˘pЉto¯-pro¯-so¯Јpe¯-a˘) [Љϩ ommended, esp. for the rifampin doses. prosopon, face] Narrowness of the face. There is concern that M. leprae is be- leptorhine, leptorrhine (le˘pЈtor-rı¯n) [Љ coming resistant to these drugs. Treat- ϩ rhis, nose] Having a very thin or ment is complicated in pregnant women slender nose. and in persons with glucose-6-phos- leptoscope (le˘pЈto¯-sko¯p) [Љϩskopein, phate dehydrogenase enzyme defi- to examine] An optical device for mea- short ciency, because of drug intolerance. De- suring the thickness of cell membranes. standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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Leptospira (le˘p-to¯-spı¯Јra˘) [Љϩspeira, ure are exhibited by affected boys. The coil] A genus of slender spirochetes disease is caused by faulty purine me- with hooked ends. tabolism, resulting in excessive uric L. interrogans icterohaemorrhagiae acid levels in the body. The species that causes hemorrhagic, lesion (le¯Јzhu˘n) [L. laesio, a wound] spirochetal jaundice (Weil’s disease). 1. A circumscribed area of pathologi- The bacteria are found worldwide; the cally altered tissue. 2. An injury or natural hosts are wild animals and wound. 3. A single infected patch in a dogs, which develop chronic kidney in- skin disease. fection. Humans acquire the bacteria Primary or initial lesions include from exposure to animal urine, often in macules, vesicles, blebs or bullae, chan- water such as ponds and puddles. cres, pustules, papules, tubercles, Symptomatic infection ranges from wheals, and tumors. Secondary lesions mild gastrointestinal upset to fatal liver are the result of primary lesions. They failure often in association with men- may be crusts, excoriations, fissures, ingitis. A vaccine is available for dogs. pigmentations, scales, scars, and ulcers. leptospire (le˘pЈto¯-spı¯r) Any organism Bankart l. SEE: Bankart lesion. belonging to the genus Leptospira. coin l. Solitary pulmonary nodule. leptospirosis (le˘pЉto¯-spı¯-ro¯Јsı˘s) [ЉϩЉ degenerative l. A lesion caused by or ϩ osis, condition] Condition resulting showing degeneration. from Leptospira infection. SYN: spiro- Dieulafoy l. [Georges Dieulafoy, Fr. chetal jaundice. physician, 1839–1911] A vascular de- leptospiruria (le˘pЉta˘-spı¯r-u¯rЈe¯-a˘, −oorЈ)[Љ fect in the mucosa of the gastrointesti- ϩЉϩouron, urine] The presence of nal tract (typically the stomach, but Leptospira in the urine. sometimes other organs) in which an ar- leptotene (le˘pЈto¯-te¯n) [Љϩtainia, rib- teriole protrudes into the lumen and bon] The initial stage of the prophase bleeds briskly. Dieulafoy lesions are an of cell division. The chromosomes be- uncommon cause of massive gastroin- come visible as separate entities but are testinal blood loss. The bleeding can be not yet paired. controlled with cauterization, rubber leptothricosis (le˘pЉto¯-thrı¯-ko¯Јsı˘s) [Љϩ banding, wedge resection, or other tech- thrix, hair] Disease caused by the niques. gram-negative bacillus Leptothrix. diffuse l. A lesion spreading over a Leptus autumnalis (le˘pЈtu˘s) Parasitic large area. mite larvae causing itch and sometimes focal l. A lesion of a small definite wheals. SEE: chiggers. area. Leriche’s syndrome (le˘-re¯shЈe˘z) [Rene´ gross l. A lesion visible to the eye Leriche, Fr. surgeon, 1879–1955] Oc- without the aid of a microscope. clusion of the abdominal aorta by a indiscriminate l. A lesion affecting thrombus at its bifurcation. This causes separate systems of the body. intermittent ischemic pain (i.e., claudi- initial l. of syphilis A hard chancre. cation) in the lower extremities and but- SEE: chancre; syphilis. tocks, impotence, and absent or dimin- lower motor neuron l. An injury oc- ished femoral pulses. curring in the anterior horn cells, nerve Leri’s pleonosteosis (la¯Јre¯z) [Andre´ roots, or peripheral nervous system that Leri, Fr. physician, 1875–1930] A form results in diminished reflexes, flaccid of hereditary physical malformation paralysis, and atrophy of muscles. characterized by upward slanting pal- low-grade squamous intraepithelial pebral fissures, broad thumbs, short l. ABBR: LGSIL. A cytological abnor- stature, and flexion contractures of the mality found in Pap tests where there fingers. are early mild changes in the epithelial lesbian (le˘sЈbe¯-a˘n) [Gr. lesbios, pert. to cells covering the outside of the cervix. island of Lesbos] 1. Pert. to lesbianism Causes include infection with human or sexual intercourse between women. papillomavirus, cervical trauma, or SEE: bisexual; homosexual. 2. A woman postmenopausal changes. Risk factors who has sex exclusively with women. include intercourse with multiple sex lesbianism (le˘zЈbe¯-a˘n-ı˘zm) Sexual con- partners or a partner with multiple sex gress preferentially or exclusively be- partners, unprotected sex at a young tween women. It was named for the Is- age, history of sexually transmitted dis- land of Lesbos, where the practice of ease, and tobacco use. About 60% of lesbianism was reputed to have been LGSIL will spontaneously resolve. If left widespread in ancient Greek history. untreated, a small number of women SYN: sapphism. eventually develop cervical cancer. Lesch-Nyhan disease (le˘shЈnı¯Јa˘n) [Mi- peripheral l. A lesion of the nerve chael Lesch, b. 1939, William Leo Ny- endings. han, b. 1926, U.S. pediatricians] An X- primary l. The first lesion of a dis- linked recessive metabolic disease, in ease, esp. used in referring to chancre of which mental retardation, aggressive syphilis. short behavior, self-mutilation, and renal fail- reverse Hill Sachs l. An indentation standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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fracture of the anteromedial humeral exists. Corticosteroids and antineoplas- head that occurs following a posterior tic drugs are used in the more severe dislocation of the glenohumeral joint. forms of the disease, but many children The cartilage of the humeral head is die of pulmonary failure or overwhelm- damaged, causing instability that may ing infections despite treatment. SEE: predispose the individual to subsequent histiocytosis, Langerhans cell. posterior glenohumeral dislocations. letter of intent Formal written notice TREATMENT: Usually no surgical in- given by one party to another of a com- tervention is required when less than mitment to pursue an action, e.g., of a approx. 25% of the articular surface is plan to bring suit against another party involved in the fracture. When the or to take on an assignment on behalf of glenoid fossa is also fractured, shoulder that party. arthroplasty may be required. Leu Conventional symbol for the amino structural l. A lesion that causes a acid leucine. change in tissue. leuc- SEE: leuko-. systemic l. A lesion confined to or- leucine (looЈsı˘n) [Gr. leukos, white] An gans of common function. essential amino acid, C6H13NO2; it can- toxic l. A lesion resulting from poi- not be synthesized by the liver and must sons or toxins from microorganisms. be present in the diet; required for pro- vascular l. A lesion of a blood vessel. tein synthesis. It is present in body tis- LET linear energy transfer. A measure of sues and is essential for normal growth the rate of energy transfer from ionizing and metabolism. radiation to soft tissue. leucine aminopeptidase ABBR: LAP. A lethal [Gr. lethe, oblivion] Pert. to or that proteolytic enzyme present in the pan- which causes death. creas, liver, and small intestine. Its se- lethality (le¯-tha˘lЈı˘-te¯) The propensity for rum level is elevated in disease of the a disease or injury to cause death, pancreas, esp. acute pancreatitis, and in rather than disability, illness, or pain. obstruction of the common bile duct. lethargy (le˘thЈa˘r-je¯) [Gr. lethargos, leucine-rich repeat kinase 2 ABBR: drowsiness] Sleepiness, drowsiness, LRRK2. Dardarin. somnolence, or mental sluggishness. leucinosis (looЉsı˘n-o¯Јsı˘s) [Љϩosis, con- induced l. A hypnotic trance. lethar- dition] Maple syrup urine disease. gic (la˘-thahrЈjı˘k), adj. leucinuria (looЉsı˘n-u¯ Јre¯-a˘) [Љϩouron, lethe (le¯Јthe¯) [Gr., oblivion] Amnesia. urine] The presence of leucine in urine. Letterer-Siwe disease (le˘tЈe˘r-e˘r-sı¯Јwe¯) leucovorin (loo-ko˘vЈo˘-rı˘n) Folinic acid, [Erich Letterer, Ger. physician, b. 1895; the active form of folic acid in the body. S. August Siwe, Ger. physician, 1897– It is used to treat anemia and as an an- 1966] The most common of three dis- tidote to protect normal cells from high tinct histiocytosis syndromes collec- doses of the anticancer drug methotrex- tively known as Langerhans cell histio- ate and to increase the antitumor effects cytosis, marked by proliferation of of fluorouracil (5-FU) and tegafur-ura- histiocytes in the viscera, bones, and cil. SYN: citrovorum factor. skin. It is believed that this disease and leuk- SEE: leuko-. the other two forms—eosinophilic gran- leukapheresis (looЉka˘-fe˘-re¯Јsı˘s) [Љϩ uloma of bone and Hand-Schu¨ller- aphairesis, removal] The separation of Christian syndrome—share a common leukocytes from blood, which are then pattern of granulomatous lesions with transfused back into the patient. histiocyte proliferation. leukemia (loo-ke¯Јme¯-a˘) [Gr. leukos, The cutaneous lesions often develop white, ϩ haima, blood] Any of a class during infancy or early childhood and in of hematological malignancies of bone some cases are present at birth. These marrow cells in which immortal clones lesions include papulovesicular erup- of immature blood cells multiply at the tions; inflamed, pruritic diaper area expense of normal blood cells. As nor- rashes; and scaly scalp lesions, all of mal blood cells are depleted from the which can be misdiagnosed as “cradle body, anemia, infection, hemorrhage, or cap” (seborrheic dermatitis of the scalp) death result. The leukemias are cate- or severe diaper rash. When the disease gorized as chronic or acute; by the cell is confined to the skin, spontaneous res- type from which they originate; and by olution in infancy may occur. In sys- the genetic, chromosomal, or growth temic presentations, the spleen and factor aberration present in the malig- liver are enlarged, pulmonary infiltra- nant cells. tion is widespread, and bone marrow Chronic leukemias, which have a rel- failure is accompanied by fever and in- atively slow course, include chronic lym- fections. The cause of the disease is un- phocytic (CLL), chronic myelogenous or known. granulocytic (CML), and hairy cell leu- DIAGNOSIS: Diagnosis is based on kemia (a subtype of CLL). Median sur- results of a skin biopsy performed with vival in these illnesses is about 4 yr. special staining techniques. Acute leukemias include acute lym- short TREATMENT: No specific treatment phocytic (ALL) and acute myeloid (my- standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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elogenous) (AML) leukemia. If un- and providing comfort, education, and treated, these diseases are fatal within psychological support. The specific weeks or months. Each of these types of needs of patients (many of whom are leukemia is discussed in subentries, be- children) and their families must be low. SEE: Nursing Diagnoses Appendix. considered. Instruction is provided ETIOLOGY: All the different molecu- about drugs the patient will receive, in- lar events leading to the development of cluding any adverse reactions and mea- unchecked cellular reproduction in the sures that will be taken to prevent or leukemias result from genetic or chro- alleviate these effects. Prescribed mosomal lesions in blood-forming cells. chemotherapy is administered with spe- Duplications of genetic material (hyper- cial precautions when indicated for in- diploidy), loss of genetic information fusion and drug disposal. If the chemo- (hypodiploidy), inactivation of genes therapy causes weight loss or anorexia, that normally suppress tumor develop- nutritional guidance is provided. Oral, ment, chromosomal translocations, and skin, and rectal care must be meticu- the release of abnormal fusion proteins lous, e.g., the nurse must thoroughly can all cause leukemia. These genetic clean the skin before all invasive pro- lesions in turn can be produced by vi- cedures, inspect the patient for peri- ruses, ionizing radiation, chemothera- rectal erosions, use strict aseptic tech- peutic drugs, and toxic chemicals. nique when starting an intravenous Rarely, leukemias are caused by famil- line, and change sets (i.e., intravenous ial genetic syndromes (e.g., as ataxia tubing and associated equipment) ac- telangiectasia, Bloom’s syndrome, or cording to chemotherapeutic protocols. Fanconi’s syndrome). Ports are irrigated according to agency SYMPTOMS: Clinical findings such as protocol. If the patient is receiving in- anemia, fatigue, lethargy, fever, and trathecal chemotherapy, the lumbar bone and joint pain may be present. puncture site is checked frequently for Physical findings include combinations bleeding or oozing. The patient and fam- of pallor, petechiae, or purpura; mucous ily are taught to recognize signs of in- membrane bleeding; enlarged liver, fection (fevers, chills, sore throat, cough, spleen, and kidneys; and tenderness urinary difficulties) and are urged to re- over the sternum and other bones. port these to the oncologist/hematolo- DIAGNOSIS: Microscopic examina- gist promptly. To prevent infection in tion of peripheral blood and specimens neutropenic patients, strict hand hy- of bone marrow are used to establish the giene protocols, special diets, and (in diagnosis. These studies are followed by hospitalized patients) laminar airflow cytochemical and cytogenetic studies of or other reverse isolation measures are abnormal cells found in the marrow or instituted. The patient is monitored for the peripheral blood to confirm the di- bleeding. If bleeding occurs, compresses agnosis with special stains and chro- are applied and the bleeding site is ele- mosomal analysis. Leukemic cells can vated. Transfusions of platelets and also be identified by flow cytometry and other blood cells are often needed. Com- immunocytochemistry, which rely on plications associated with specific antibodies binding to and helping to chemotherapeutic regimens (e.g., hair identify malignant cells. The spread of loss, nausea and vomiting, anemia, neu- leukemias to internal organs (e.g., the tropenia, and low platelets) are ex- brain, the kidneys, or the lungs) may be plained to the patient, along with man- evaluated with imaging tests (e.g., MRI agement strategies that will be studies, CT scans, or ultrasound). employed. Prescribed analgesics are ad- TREATMENT: Chemotherapy, bone ministered as needed, and noninvasive marrow transplantation, or both are pain relief techniques and comfort mea- used to treat leukemias. Regimens are sures (e.g., position changes, cutaneous devised regularly and are tailored to stimulation, distraction, relaxation specific illnesses. Treatment is often breathing, and imagery) may be used. given in several phases, with a period Gentle oral hygiene measures and pro- of induction chemotherapy to induce tective skin care are explained. Fluid in- remission by completely eliminating take should be increased to eliminate leukemic cells from the bone marrow, chemotherapy metabolites, and the pa- followed by consolidation and mainte- tient advised to void more frequently to nance phases. This multiphase treat- prevent cystitis. Dietary fiber is impor- ment is designed to further deplete ma- tant, and stool softeners may be used to lignant cells from the bone marrow and ensure normal bowel movements. Anti- to achieve complete cure. diarrheals usually control diarrhea, but PATIENT CARE: Patient care mea- the patient should be monitored for sures focus on eradicating the illness; signs of dehydration. Fatigue is an an- managing complications; minimizing ticipated adverse effect of treatment; the effects of chemotherapy; preserving therefore the patient is encouraged to veins (often an indwelling port is in- alternate activity with rest periods and short serted to administer chemotherapy); to obtain assistance with daily activities standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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as necessary. Reproductive issues mercaptopurines, and other cytotoxic should be discussed with the patient. agents. Prophylaxis against central ner- Patient care routines and visiting times vous system disease is accomplished by should be flexible when hospitalization intrathecal drug administration. In re- is required. The patient and family are ferral hospitals, allogeneic stem cell encouraged to participate in care as transplantation is sometimes used for much as possible. Referrals are made to refractory disease. About 90% of treated social service agencies, home health children achieve remission. The 5-year care agencies, and support groups. If the survival of children with ALL is about patient does not respond to treatment 85%. Adult ALL is much less responsive and has reached the terminal phase of to therapy; only about a third of adult the disease, supportive nursing, pallia- patients are cured. In both childhood tive care, or hospice care should be dis- and adult ALL, allopurinol and hydra- cussed sensitively with patients and tion precede induction chemotherapy to their caregivers. prevent hyperuricemia caused by tumor acute lymphoblastic l. Acute lym- lysis. phocytic leukemia. PROGNOSIS: Late complications of acute lymphocytic l. ABBR: ALL. A therapy are not uncommon. hematological malignancy marked by acute myelogenous l. ABBR: AML. the unchecked multiplication of imma- Acute myeloid leukemia. ture lymphoid cells in the bone marrow, acute myeloid l. ABBR: AML. Any blood, and body tissues. In 2008 the of a group of hematological malignan- American Cancer Society estimated cies in which neoplastic cells develop about 5400 Americans would be diag- from myeloid, monocytic, erythrocytic, nosed with ALL. It is rapidly fatal if left or megakaryocytic precursors. AML is untreated. SYN: acute lymphoblastic l. four times more common in adults than SEE: illus; leukemia. acute lymphocytic leukemia (ALL). In ETIOLOGY: Any of a wide range of ac- 2008, the American Cancer Society es- quired or congenital chromosomal ab- timated about 13,300 Americans would normalities can cause ALL, including be diagnosed with AML, and that the lesions that result in the release of ex- disease would cause 8,800 deaths. It oc- cess growth factors from cells and those casionally follows a myelodysplastic dis- that cause the loss of cancer-suppress- order or aplastic anemia and sometimes ing genes. occurs as a consequence of a familial dis- SYMPTOMS: Fatigue, lethargy, bleed- order of fragile chromosomes (e.g., Fan- ing, bone and joint pain, and a predis- coni’s syndrome). position to fever and infection are char- All forms of AML are marked by neo- acteristic of ALL and other leukemias. plastic replacement of normal bone DIAGNOSIS: The disease is suggested marrow and circulation of immature by the presence of abnormalities on the cells (“blasts”) in the peripheral blood. complete blood count or peripheral Anemia and thrombocytopenia com- blood smear and is confirmed by im- monly occur. The central nervous sys- munophenotyping. tem and other organs are occasionally TREATMENT: In childhood, ALL in- invaded. Complete remissions occur in duction chemotherapy often begins with approximately 65% of treated patients; steroids, vinca alkaloids, and asparagi- responses to treatment lasting 5 years nase. This is followed, after bone mar- are achieved in 15% to 25% of treated row recovery, by consolidation chemo- patients. SYN: acute myelogenous l.; therapy with multidrug regimens, acute nonlymphocytic l. including high-dose methotrexate. ETIOLOGY: Genetic and chromo- Maintenance therapies, which may last somal aberrations, such as are found in 2 years or longer, include methotrexate, other leukemias, are characteristic.

ACUTE LYMPHOCYTIC LEUKEMIA short (A) Peripheral blood (Orig. mag. ϫ640), (B) bone marrow (Orig. mag. ϫ640) standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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SYMPTOMS: Exertional fatigue as a hematological malignancy marked by a result of anemia, bleeding due to throm- sustained increase in the number of bocytopenia, and infections due to a lack granulocytes, splenic enlargement, and of normal white blood cells are common. a specific cytogenetic anomaly (the TREATMENT: Cytotoxic chemothera- “Philadelphia chromosome”) in the bone pies, with an induction phase followed marrow of more than 90% of patients. by consolidation, are used. Typically, cy- The disease affects one or two people tosine arabinoside and an anthracycline per 100,000. In 2008 the American Can- are used during induction for AML. Al- cer Society estimated that 4830 people logeneic bone marrow transplantation would be diagnosed with CML and that is used when a matching donor is avail- 450 would die of the disease. The course able; stem cell transplantation is an op- of the disease has three phases: a tion for some patients with specific cyto- chronic one in which blood counts are genetic abnormalities. relatively easy to control with medica- acute nonlymphocytic l. ABBR: tions; an accelerated phase in which ANLL. Acute myeloid leukemia. granulocyte counts become more resis- aleukemic l. Leukemia cutis. tant to chemotherapy; and a “blast” cri- chronic lymphocytic l. ABBR: CLL. sis, which resembles acute leukemia. A malignancy in which abnormal lym- Median survival is about 4 years. It gen- phocytes (usually B cells) proliferate erally occurs between ages 40 and 50, and infiltrate body tissues, often caus- affecting slightly more men than women ing lymph node enlargement and im- (4600 adults in the U.S. in 2005). SYN: mune dysfunction. Infectious complica- chronic myelogenous l. SEE: leukemia. tions are common. Median life ETIOLOGY: CML results from a expectancy is about 4 years. Chronic translocation of genetic material be- lymphocytic leukemia is the most com- tween chromosomes 9 and 22. The mon leukemia in industrialized nations. translocation results in the production It usually occurs in people (older men) of an abnormal tyrosine kinase that above age 60. Its incidence rises to 20 makes affected cells immortal. cases per 100,000 in people over 80. In SYMPTOMS: CML often is diagnosed 2008 the American Cancer Society es- in asymptomatic patients who are found timated that 15,100 people would be di- to have an unexplained leukocytosis agnosed with CLL and that 4,400 would when their complete blood counts are die of the disease. The timing of treat- checked. Subsequent evaluation, in- ment and the prognosis in CLL depend cluding bone marrow aspiration and bi- on the stage of the disease. Staging in- opsy with cytogenetic analysis, reveal cludes such factors as the number of ab- the Philadelphia chromosome. normal lymphocytes in the bloodstream, TREATMENT: Imatinib mesylate (a how quickly they double, and the pres- drug that blocks an abnormal kinase ence of lymphadenopathy, organomeg- made by Philadelphia chromosome pos- aly, or cytopenias. SEE: illus. itive CML cells) effectively reduces the TREATMENT: Patients with ad- number of tumor cells in the chronic vanced stages of the illness are often phase of CML to normal in nearly 90% treated with chlorambucil, fludarabine, of patients. An alternative is stem cell or other cytotoxic agents, often with ri- transplantation. tuximab (a monoclonal antibody) added l. cutis An invasion of the dermis and to enhance response. Patients with subcutaneous fat by leukemic cells. The early-stage disease are not usually invasion often happens before these given therapy. cells proliferate in the bone marrow or chronic myelogenous l. ABBR: are detectable in the peripheral blood. CML. Chronic myeloid leukemia. The cells may cause several different chronic myeloid l. ABBR: CML. A types of skin rashes, including blue nod-

CHRONIC LYMPHOCYTIC LEUKEMIA short (A) Peripheral blood (Orig. mag. ϫ400), (B) bone marrow (Orig. mag. ϫ640) standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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ules (giving the skin a “blueberry muf- leukocidin (loo-ko¯-sı¯Јdı˘n) [ЉϩL. cae- fin” appearance), papules, plaques, and dere, to kill] A bacterial toxin that de- ulcers. SYN: aleukemic l. stroys leukocytes. hairy cell l. ABBR: HCL. A chronic, leukocoria, leukokoria (looЉko¯-ko˘rЈe¯-a˘) [Љ low-grade hematological malignancy of ϩ Gr. kore, girl, pupil of the eye] White abnormally shaped B lymphocytes or abnormal pupillary reflex. This reflex (“hairy cells”). The disease is marked by may be present in infants and children pancytopenia and splenomegaly. Me- who have retinoblastoma, cataract, ret- dian survival in untreated patients is inal detachment, and intraocular infec- about 5 years. The disease is rare, being tions. Patients with this reflex should be only 1% to 2% of all leukemias. The me- referred to an ophthalmologist without dian age of patients is 50 years; men are delay. affected more commonly than women by leukocyte (looЈko¯-sı¯t) [Љϩkytos, cell] a 4-to-1 ratio. SEE: illus. A white blood cell (WBC). There are two types: granulocytes (those possessing, in their cytoplasm, large granules that stain different colors under a micro- scope) and agranulocytes (those lacking granules). Granulocytes include baso- phils, eosinophils, and neutrophils. Agranulocytes include monocytes and lymphocytes. Clinically, granulocytes are often referred to as “polys” because they are all polymorphonuclear (multi- lobed nuclei); whereas agranulocytes are mononuclear (one nucleus). SEE: blood for illus. Neutrophils, 55% to 70% of all WBCs, LYMPHOCYTES IN HAIRY CELL LEUKEMIA are the most numerous phagocytic cells ϫ and are a primary effector cell in inflam- (Orig. mag. 640) mation. Eosinophils, 1% to 3% of total SYMPTOMS: Weight loss, hyperme- WBCs, destroy parasites and are in- tabolism, infectious complications, and volved in allergic reactions. Basophils, abdominal discomfort due to splenic en- less than 1% of all WBCs, contain gran- largement are common. ules of histamine and heparin and are TREATMENT: Cladribine, pentosta- part of the inflammatory response to in- tin, 2-chlorodeoxyadenosine, and flu- jury. Monocytes, 3% to 8% of all WBCs, darabine have been used. become macrophages and phagocytize PROGNOSIS: Before the availability pathogens and damaged cells, esp. in of the chemotherapeutic agents, the the tissue fluid. Lymphocytes, 20% to mean survival time was 4.6 years for 35% of all WBCs, have several func- nonsplenectomized patients and 6.4 for tions: recognizing foreign antigens, pro- those who had splenectomy. The use of ducing antibodies, suppressing the im- chemotherapy in HCL patients may mune response to prevent excess tissue permit longer survival times. damage, and becoming memory cells. leukemic (loo-ke¯mЈ˘k)ı [Љϩhaima, Leukocytes are formed from the un- blood] 1. Relating to leukemia. 2. Af- differentiated stem cells that give rise to fected with leukemia. all blood cells. Those in the red bone leukemid (loo-ke¯Јmı˘d) Any nonspecific marrow may become any of the five skin lesion associated with leukemia. kinds of WBCs. Those in the spleen and The lesions may or may not contain leu- lymph nodes may become lymphocytes kemic cells. or monocytes. Those in the thymus be- leukemogenesis (loo-ke¯Љmo¯-je˘nЈe˘-sı˘s) [Љ come lymphocytes called T lympho- ϩЉϩgenesis, generation, birth] The cytes. induction of leukemia. FUNCTION: Leukocytes are the pri- leukin (looЈkı˘n) A thermostable bacteri- mary effector cells against infection and cidal substance present in leukocytes. tissue damage. They not only neutralize leuko-, leuk-, leuc- [Gr. leukos, white] or destroy organisms, but also act as Combining forms meaning white or scavengers, engulfing damaged cells by white corpuscle. phagocytosis. Leukocytes travel by ame- leukoagglutinin (looЉko¯-a˘-glooЈtı˘-nı˘n) [Љ boid movement and are able to pene- ϩ L. agglutinans, gluing] An antibody trate tissue and then return to the that agglutinates white blood cells. bloodstream. Their movement is di- leukoareosis (loo-koh-ar-ee-ohЈsis) An rected by chemicals released by injured abnormal appearance of the periventric- cells, a process called chemotaxis. After ular white matter of the brain, seen in coming in contact with and recognizing people with poorly controlled hyperten- an antigen, neutrophils or macrophages sion, Alzheimer’s disease, and other phagocytize (engulf) it in a small vacu- short conditions. ole that merges with a lysosome, to per- standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh leukocyte 1327 leukocytotoxin base of rh

mit the lysosomal enzymes to digest the leukocyte reduction The removal of phagocytized material. When leuko- white blood cells from blood prior to its cytes are killed along with the patho- transfusion, to decrease the likelihood genic organisms they have destroyed, of transfusion reactions or infection of the resulting material is called pus, the recipient with viral diseases. commonly found at the site of localized leukocytic (looЉko¯-sı˘tЈ˘k)ı [Љϩkytos, infections. Pus that collects because of cell] Pert. to leukocytes. inadequate blood or lymph drainage is leukocytoblast (looЉko¯-sı¯Јto¯-blast) [Љϩ called an abscess. Љϩblastos, germ] A cell from which Microscopic examination: Leukocytes a leukocyte arises. can be measured in any bodily secretion. leukocytogenesis (looЉko¯-sı¯Љto¯-je˘nЈe˘-sı˘s) They are normally present in blood and, [Љϩkytos, cell, ϩ genesis, genera- in small amounts, in spinal fluid and tion, birth] Leukopoiesis. mucus. The presence of WBCs in urine, leukocytoid (looЈko¯-sı¯Љtoyd) [ЉϩЉϩ sputum, or fluid drawn from the abdo- eidos, form, shape] Resembling a leu- men is an indication of infection or kocyte. trauma. The type of WBC present is leukocytolysin (looЉko¯-sı¯-to¯lЈı˘-sı˘n) A ly- identified by the shape of the cell or by sin that destroys leukocytes. SEE: leu- the use of stains (Wright’s) to color the kocidin. granules: granules in eosinophils stain leukocytolysis (looЉko¯-sı¯-to˘lЈı˘-sı˘s) [Љϩ red, those in basophils stain blue, and kytos, cell, ϩ lysis, dissolution] De- those in neutrophils stain purple. struction of leukocytes. Clinically, WBC counts are important leukocytoma (looЉko¯-sı¯-to¯Јma˘) [ЉϩЉ in detecting infection or immune system ϩ oma, tumor] 1. A tumor composed of dysfunction. The normal WBC level is cells resembling leukocytes. 2. A tumor- 5000 to 10,000/mm3. An elevated like mass of leukocytes. (greater than 10,000) leukocyte count leukocytopenia (looЉko¯-sı¯Љto¯-pe¯Јne¯-a˘) [Љ (leukocytosis) indicates an acute infec- ϩЉϩpenia, want] Leukopenia. tion or inflammatory disease process leukocytopoiesis (looЉko¯-sı¯Љto¯-poy-e¯Јsı˘s) (such as certain types of leukemia), [ЉϩЉϩpoiein, to make] The for- whereas a decrease in the number of mation of white blood cells. leukocytes (less than 5000) indicates ei- leukocytosis (looЉko¯-sı¯-to¯Јsı˘s) [Љϩky- ther immunodeficiency or an over- tos, cell, ϩ osis, condition] An in- whelming infection that has depleted crease in the number of leukocytes (usu- WBC stores. In addition to the total ally above 10,000/mm3) in the blood. It WBC count, the differential count is occurs most commonly in disease pro- also frequently important. A differential cesses involving infection, inflamma- count measures the percent of each type tion, trauma, or stress, but it also can of WBC (e.g., neutrophils, monocytes, result occasionally from the use of some lymphocytes). The differential also mea- medications (e.g., corticosteroids). SEE: sures the number of immature cells of leukemoid; leukocyte; leukopenia. each cell type as an indication of pro- It usually is caused by an increase in duction by the bone marrow. Immature one particular type of white blood cell cells are called “blasts” (e.g., lympho- (WBC). For example, neutrophils in- blasts, myeloblasts). During infections crease in acute bacterial infections and or in certain types of leukemia, blasts inflammation, monocytes increase in may be present in peripheral blood. chronic infections, lymphocytes in- SEE: inflammation. crease in viral and chronic bacterial in- acidophilic l. Eosinophil. fections, and eosinophils increase in al- agranular l. Nongranular l. lergic disorders, such as asthma. basophilic l. Basophil. Leukemias often cause a huge increase eosinophilic l. Eosinophil. in circulating cells, owing to the un- granular l. A leukocyte containing checked reproduction of a single clone of granules in cytoplasm. malignant cells. heterophilic l. A neutrophilic leuko- basophilic l. An increase in the ba- cyte of certain animals whose granules sophils in the blood. stain with an acid stain. mononuclear l. An increase in the lymphoid l. Nongranular l. monocytes in the blood. neutrophilic l. Neutrophil. pathological l. Leukocytosis due to a nongranular l. An agranulocyte; a disease such as an infection. lymphocyte or monocyte. SYN: agranu- leukocytotaxis (looЉko¯-sı¯Љto¯-ta˘kЈsı˘s) [Gr. lar leukocyte; lymphoid leukocyte. leukos, white, ϩ kytos, cell, ϩ taxis, polymorphonuclear l. ABBR: PMN. arrangement] The movement of leuko- A white blood cell with a nucleus made cytes either toward or away from an of two or more lobes, i.e., the granular area such as a traumatized or infected leukocytes: neutrophils, eosinophils, or site. basophils. SYN: polysegmented neutro- leukocytotoxin (looЉko¯-sı¯Љto¯-to˘kЈsı˘n) [Љ phil. SEE: basophil; eosinophil; neutro- ϩЉϩtoxikon, poison] A toxin that short phil. destroys leukocytes. SYN: leukotoxin. standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh leukoderma 1328 leukoplakia base of rh leukoderma (loo-ko¯-de˘rЈma˘) [Љϩ caine, toluene, and some cytotoxic derma, skin] Deficiency of skin pigmen- drugs. tation, esp. in patches. SEE: vitiligo. SYMPTOMS: Confusion, disinterest, syphilitic l. Macular depigmentation, lethargy, memory losses, and psychiat- esp. of the skin of the neck and shoul- ric symptoms are common in early ders, seen in late syphilis. stages. Profoundly ill patients may dis- leukodystrophy (looЉko¯-dı˘sЈtro¯-fe¯) Any play stupor or coma. Language distur- disease (such as globoid cell leukodys- bances are unusual. trophy, adrenoleukodystrophy, or meta- leukoerythroblastosis (looЉko¯-e˘-rı˘thЉro¯- chromatic leukodystrophy) whose hall- bla˘s-to¯Јsı˘s) [Љϩerythros, red, ϩ marks are metabolic defects in the blastos, germ, ϩ osis, condition] Ane- formation of myelin. Bone marrow mia due to any condition that causes the transplantation can cure some affected bone marrow to be infiltrated and thus children. inactivated. metachromatic l. A type of heredi- leukokeratosis (looЉko¯-ke˘r-a˘-to¯Јsı˘s) [Љϩ tary leukodystrophy caused by a defi- keras, horn, ϩ osis, condition] Leu- ciency of the enzyme cerebroside sulfa- koplakia. tase, an enzyme that is essential for the leukokraurosis (looЉko¯-kraw-ro¯Јsı˘s) [Љϩ degradation of sulfatide. Deficiency of krauros, dry, ϩ osis, condition] Li- the enzyme allows excess deposition of chen sclerosis et atrophicus. sulfatide in nerve tissues. Clinical signs leukolymphosarcoma (looЉko¯-lı˘mЉfo¯-sa˘r- of this disease usually appear at about ko¯Јma˘) [ЉϩL. lympha, lymph, ϩ 1 year of age. They include gait distur- Gr. sarx, flesh, ϩ oma, tumor] Lym- bance, inability to learn to walk, spas- phosarcoma cell leukemia. ticity of the limbs, hyperreflexia, de- leukoma (loo-ko¯Јma˘) [Љϩoma, tumor] mentia, and eventually death. The A white, dense corneal opacity. disease, for which there is no specific l. adherens A corneal opacity to therapy, is usually fatal by age 10. which the iris is attached. leukoedema (looЉko¯-e˘-de¯Јma˘) [Љϩoi- leukomatous (loo-ko¯Јma˘-tu˘s) [Gr. leu- dema, swelling] A benign leukophakia- kos, white, ϩ oma, tumor] 1. Pert. to like abnormality of the mucosa of the leukoma. 2. Suffering from leukoma. mouth or tongue. The affected areas are leukomyelitis (looЉko¯-mı¯-e˘-lı¯Јtı˘s) [Љϩ opalescent or white, and wrinkled. myelos, marrow, ϩ itis, inflammation] leukoencephalitis (looЉko¯-e˘n-se˘f-a˘-lı¯Јtı˘s) Inflammation of the white matter of the [Љϩenkephalos, brain ϩ itis, inflam- spinal cord. mation] Inflammation of the white leukomyelopathy (looЉko¯-mı¯-e˘l-o˘pЈa˘-the¯) matter of the brain. [ЉϩЉϩpathos, disease] Disease in- acute hemorrhagic l. A neurological volving the white matter of the spinal syndrome marked by rapidly progres- cord. sive neurological findings, associated leukonecrosis (looЉko¯-ne˘-kro¯Јsı˘s) [Љϩ with asymmetric inflammatory patho- nekrosis, state of death] Dry, light-col- logical changes in the brain, and bleed- ored, or white gangrene. ing. SYN: Weston Hurst syndrome. leukonychia (looЉko¯-nı˘kЈe¯-a˘) [Љϩonyx, leukoencephalopathy (looЉko¯-e˘n-se˘f-a˘- nail] White spots or streaks on the lo˘Јpa˘-the¯) [Gr. leukos, white, ϩ en- nails. SYN: canities unguium; leukopa- kephalos, brain, ϩ pathos, disease, thia unguium. suffering] Damage to the white matter leukopathia (looЉko¯-pa˘thЈe¯-a˘) [Љϩpa- of the brain, especially to myelin. thos, disease] 1. The absence of pig- leukoencephalopathy, progressive mul- ment in the skin. SEE: leukoderma. 2. A tifocal ABBR: PML. A disease char- disease involving leukocytes. acterized by the presence of widespread l. unguium Leukonychia. demyelinating lesions of the brain, leukopedesis (looЉko¯-pe˘-de¯Јsı˘s) [Љϩpe- brainstem, and/or cerebellum. It is dan, to leap] The passage of leukocytes caused by infection with polyoma JC vi- through the walls of the blood vessels. rus. PML is usually associated with leukopenia (looЉko¯-pe¯Јne¯-a˘) [Љϩpenia, chronic, immune suppressing illnesses, lack] Abnormal decrease of white blood such as AIDS, and some lymphomas or cells usually below 5000/mm3. A great leukemias. Clinical findings include number of drugs may cause leukopenia, aphasia, ataxia, blindness, dementia, as can failure of the bone marrow. SYN: dysarthria, and eventual coma. The dis- granulocytopenia; leukocytopenia. ease is sometimes diagnostically con- leukoplakia (looЉko¯-pla¯Јke¯-a˘) [Љϩplax, fused with multiple sclerosis. plate] Formation of white spots or leukoencephalopathy, toxic Damage to patches on the mucous membrane of the the white matter of the brain caused by tongue or cheek. The spots are smooth, exposure to chemicals, radiation, and irregular in size and shape, hard, and certain viruses, including HIV. The occasionally fissured. The lesions may chemical agents include, but are not become malignant. SYN: leukokoria; short limited to, alcohol, carbon monoxide, co- leukoplasia. standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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l. buccalis Leukoplakia of the mu- arrangement] Possessing the power of cosa of the cheek. attracting leukocytes. oral hairy l. Leukoplakia of the leukotaxis (looЉko¯-ta˘ksЈı˘s) Possessing tongue. SEE: illus. the power of attracting (positive leuko- taxis) or repelling (negative leukotaxis) leukocytes. leukotomy (loo-ko˘tЈo¯-me¯) [Љϩtome, in- cision] Lobotomy. leukotoxic (looЉko¯-to˘ksЈ˘k)ı [Љϩtoxi- kon, poison] Destructive to leukocytes. leukotoxin (looЉko¯-to˘kЈsı˘n) [Љϩtoxi- kon, poison] Leukocytotoxin. leukotrichia (looЉko¯-trı˘kЈe¯-a˘) [Љϩthrix, hair] Whiteness of the hair. SYN: can- ities. leukotriene (looЉko¯-trı¯Јe¯n) Any of a group of arachidonic acid metabolites that functions as a chemical mediator of ORAL HAIRY LEUKOPLAKIA allergic reactions and inflammation. Leukotrienes C4,D4, and E4 are derived In a patient with AIDS from the precursor molecule leukotriene A4. The subscripted number specifies l. vulvae Lichen sclerosis et atrophi- the number of double bonds in the mol- cus. ecule. All are synthesized by cells in re- Ј leukoplasia (loo-ko¯-pla¯ ze¯-a˘) Leuko- sponse to inflammation or tissue injury. plakia. Leukotrienes have been implicated in Љ Ј Љϩ leukopoiesis (loo ko¯-poy-e¯ sı˘s) [ the development of the inflammatory poiesis, formation] Leukocyte produc- responses in asthma, psoriasis, rheu- tion. SYN: leukocytogenesis. leukopoi- matoid arthritis, and inflammatory Ј etic (−e˘t ı˘k), adj. bowel disease. They are powerful bron- leukoreduction (looЉko¯-re¯-du˘kЈshu˘n) ϩ choconstrictors and vasodilators and [Gr. leukos, white, L. reductio, lead- mediate the adverse vascular and bron- ing back] The loss of white blood cells chial effects of systemic anaphylaxis. from a unit of packed red cells by filtra- leumorphin (loo-mo˘rЈfı˘n) [ЉϩMorpheus, tion of the blood before transfusion. ancient Gr. god of dreams or sleep] An White blood cells in red cell transfusions endogenous endorphin derived from have been associated with immunosup- proenkephalin. It decreases the secre- pression in recipients. Leukoreduction tion of vasopressin and fluid intake but typically lowers the white cell content of increases feeding and opposes apopto- packed red cells from about 3 ϫ 109 per sis. unit of blood to about 2.5 ϫ 105 per unit. Levaquin SEE: levofloxacin. It has been associated with a decrease levator (le¯-va¯Јtor) pl. levatores [L., in post-transfusion fevers, and, in some lifter] 1. A muscle that raises or ele- studies, with decreased post-transfu- vates a part; opposite of depressor. 2. An sion mortality. leukorrhagia (looЉko¯-ra¯Јje¯-a˘) [Љϩrheg- instrument that lifts depressed por- nynai, to burst forth] Leukorrhea. tions. leukorrhea (looЉko¯-re¯Јa˘) [Љϩrhoia, l. ani A broad muscle that helps to flow] A white, estrogen-related, scant- form the floor of the pelvis. to-moderate, odorless, physiological l. palpebrae superioris A muscle that vaginal discharge, normally preceding elevates the upper eyelid. menarche and occurring during ovula- levator ani syndrome Chronic pain and/ tion, during pregnancy, and in response or pressure felt in the anus or high in to sexual excitement. Some women note the rectum. The cause is unknown, but an increased discharge related to oral muscular tension or spasm, nerve irri- contraceptive or hormone replacement tation, or tendonitis may contribute. therapy. Chronic cervicitis and vaginal Some patients improve with injections infections are the most common causes of corticosteroid medications. Ј of abnormal genital discharge. Signs of LeVeen shunt (la˘-ve¯n ) [Harry LeVeen, infection include increased discharge, U.S. surgeon, 1917–1997] A shunt change in color and consistency, odor, from the peritoneal cavity to the venous vulvar irritation, dysuria, and itching. circulation used to help control ascites SYN: leukorrhagia. SEE: vaginitis. by allowing ascitic fluid to enter the ve- leukosarcoma (looЉko¯-sa˘r-ko¯Јma˘) [Gr. nous circulation. leukos, white, ϩ sarx, flesh, ϩ oma, level of health care SEE: system, health tumor] A variant of lymphoma in which care. malignant cells enter the blood stream lever (le˘vЈe˘r, le¯Јve˘r) [L. levare, to raise] and circulate. A rigid bar used to modify direction, short leukotactic (looЉko¯-ta˘kЈtı˘k) [Љϩtaxis, force, and motion. A type of simple ma- standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh Levey-Jennings chart 1330 L-forms base of rh

chine that provides the user with a me- piratory tract, abdomen, skin, bones, chanical advantage. Levers are used to and joints. facilitate the moving and lifting of ob- levophobia (le˘vЉo¯-fo¯Јbe¯-a˘) [ЉϩGr. pho- jects too heavy or awkward for one to bos, fear] A morbid dread of objects on move unassisted. the left side of the body. Levey-Jennings chart (le˘vЈe¯-je˘nЈı˘ngz) levorotation (le¯Љvo¯-ro¯-ta¯Јshu˘n) [Љϩro- [S. Levey, 20th century American stat- tare, to turn] Levotorsion (1). istician; E.N. Jennings, 20th century levorotatory (le¯Љvo¯-ro¯Јta˘-tor-e¯) Causing American statistician] A graphical rep- to turn toward the left, applied esp. to resentation of control data, arranged in substances that turn polarized light chronological order, that shows a mean rays to the left. or target value and one or more sets of levothyroxine sodium (le¯Љvo¯-thı¯-ro˘kЈse¯n) acceptable limits. ABBR: T4. The sodium salt of the nat- Levine, Myra (le˘-ve¯nЈ) A nursing educa- ural isomer of thyroxine used to treat tor, died 1996, who developed the Con- thyroid deficiency. A typical dosage is servation Model of Nursing. SEE: Nurs- 1.6 mcg/kg/day given orally. ing Theory Appendix. levotorsion, levoversion (le¯Љvo¯-torЈshu˘n, Levine-Critchley syndrome (le˘-ve¯nЈ- le¯Љvo¯-ve˘rЈshu˘n) [Љϩtorsio, a twisting] krı˘chЈle¯) Neuroacanthosis. 1. A twisting to the left. SYN: levorota- Levin’s tube (le˘-vı˘nzЈ) [Abraham L. tion. 2. Levoclination. Љ Ј Levin, U.S. physician, 1880–1940] A levulinic acid (le˘v u¯-lı¯n ˘k)ı CH3COCH2- catheter that is usually introduced CH2COOH; An acid formed when cer- through the nose and extends into or tain simple sugars are acted on by dilute through the stomach. It is used to help hydrochloric acid. Ј prevent accumulation of intestinal liq- levulose (le˘-v u¯-lo¯s) SEE: fructose. Љ Ј Љϩ uids and gas during and after intestinal levulosemia (le˘v u¯-lo¯-se¯ me¯-a˘) [ Gr. surgery. This tube is often referred to as haima, blood] The presence of fructose a nasogastric tube. A variant includes in the blood. Љ Ј Љϩ the addition of a sump channel, which levulosuria (le˘v u¯-lo¯-su¯ re¯-a˘) [ Gr. helps to reduce gas build-up in the up- ouron, urine] The presence of fructose in the urine. per gastrointestinal tract. SEE: Salem Ј sump tube. lewisite (lu¯ ı˘-sı¯t) [Warren Lee Lewis, levitation (le˘vЉı¯-ta¯Јshu˘n) [L. levitas, U.S. chemist, 1878–1943] A toxic gas lightness] The subjective sensation of similar in action to mustard gas, used rising in the air or moving through the in warfare to disable and kill. It acts as air unsupported. It occurs in dreams, al- a vesicant in the lungs. Dimercaprol is tered states of consciousness, and cer- the treatment drug of choice. tain mental disorders. Lewy body (loo-we¯) [Frederic H. Lewy, Ger. neurologist, 1885–1950] A neu- levocardia (le¯Љvo¯-ka˘rЈde¯-a˘) [L. laevus, ronal cell with pigmented inclusion bod- left, ϩ Gr. kardia, heart] A term de- ies. They are found in the brain in the scribing the normal position of the heart substantia nigra and locus ceruleus, when other viscera are inverted. SEE: esp. in Parkinson’s disease. SEE: illus. dextrocardia. levocarnitine (le˘Љvo¯-ka˘rЈnı˘-te¯n) An amino acid-derived drug used in treat- ing primary carnitine deficiency. SEE: carnitine. levoclination (le¯Љvo¯-klı¯-na¯Јshu˘n) [Љϩ clinatus, leaning] Torsion or twisting of the upper meridians of the eyes to the left. SYN: levotorsion (2). levocycloduction (le¯Љvo¯-sı¯Љklo¯-du˘kЈshu˘n) [ЉϩGr. kyklos, circle, ϩ L. ducere, to lead] Levoduction. levodopa (le˘vЉo¯-do¯Јpa˘) L-3,4-dihydroxy- phenylalanine; a drug used in the treat- ment of Parkinson’s disease. Also called L-dopa. levoduction (le¯Љvo¯-du˘kЈshu˘n) [L. laevus, LEWY BODY left, ϩ ducere, to lead] Movement or Leydig cell (lı¯Јdı˘g) [Franz von Leydig, drawing toward the left, esp. of an eye. Ger. anatomist, 1821–1908] One of the SYN: levocycloduction. interstitial cells in the testicles that pro- levofloxacin (le˘vЉo¯-flo˘kЈsa˘-sı˘n) A fluoro- duce testosterone. quinolone and anti-infective, adminis- LFA left frontoanterior fetal position. tered orally to treat urinary tract and L-forms [named for Lister Institute] gynecological infections and gonorrhea. Spontaneous variants of bacteria that It is also used to treat prostatitis; infec- replicate as filterable spheres with de- short tious diarrhea; and infections of the res- fective or absent cell walls. They are fil- standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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terable because of their flexibility scious. 2. In psychoanalysis, the energy rather than their size. Stable forms may that is the driving force of human be- grow for an indefinite time in a wall-less havior. It has been variously identified state. Organisms of the unstable form as the sex urge, desire to live, desire for are capable of regenerating their cell pleasure, or satisfaction. walls and reverting to their antecedent low l. A sexual dysfunction marked bacterial form. The ability of L-forms to by inhibited sexual desire and inability cause disease is unknown. SYN: L- to sustain arousal during sexual activi- phase variants. ties. Diminished sexual drive may be re- LFP left frontoposterior fetal position. lated to advanced age, psychogenic LFT left frontotransverse fetal position. causes, general illness, side effects of LGA large for gestational age. some medications, or substance abuse. LGSIL low-grade squamous intraepithe- In men it manifests as partial or com- lial lesion. SEE: under lesion. plete failure to attain or maintain erec- LH luteinizing hormone. SEE: under hor- tion until completion of the sex act. In mone. women there is partial or complete fail- Lhermitte’s sign (la¯r-me¯tsЈ) [Jacques ure to attain or maintain the vaginal lu- Jean Lhermitte, Fr. neurologist, 1877– brication-swelling response of sexual 1959] The symptom (rather than a excitement until completion of the sex sign) of a pain resembling a sudden elec- act. SEE: table. tric shock throughout the body pro- duced by flexing the neck. It is caused Some Classes of Drugs That Inhibit by trauma to the cervical portion of the Libido spinal cord, multiple sclerosis, cervical Class Examples cord tumor, or cervical spondylosis. LHRH luteinizing hormone–releasing alcohol beer, liquor, wine hormone. SEE: under hormone. antidepressants amitriptyline, Li Symbol for the element lithium. fluoxetine liability Legal responsibility. A health alpha blockers clonidine care provider is legally responsible for beta blockers atenolol, propran- actions that fail to meet the standards olol of care or are grossly negligent, thereby drugs of abuse amphetamines, causing harm to the patient. cocaine, heroin school-specific l. The legal standard histamine2 cimetidine that holds licensed practitioners liable blockers only for those actions that violate the major tranquil- clozapine, flu- standards of their own education and izers phenazine, training. As a result, chiropractic liabil- thioridazine ity is judged based on standards of care oral contracep- many types in the school of chiropractic, while sur- tives gical liability is based on the standards sedative/hyp- benzodiazepines set forth among surgeons. notics enterprise l. The legal and financial liability of a health care institution for Ј Ј injuries that result from the actions, be- Libman-Sacks disease (lı˘b ma˘n-sa˘ks ) haviors, or negligence of its staff. [Emanuel Libman, U.S. physician, strict l. Liability attributed to a man- 1872–1946; Benjamin Sacks, U.S. phy- ufacturer or seller of a dangerous or de- sician, 1896–1939] Verrucous, nonbac- fective product regardless of proven terial endocarditis. SEE: endocarditis. negligence or fault. Libman-Sacks endocarditis An eponym vicarious l. Legal responsibility of a for nonbacterial thrombotic endocardi- health care professional or health care tis. institution for the negligent actions of library A stored, retrievable collection of data. its trainees and employees. lice Pl. of louse. libel (lı¯Јbe˘l) [L. libellus, little book, licensed occupational therapist ABBR: pamphlet] Defaming the character of LOTR; OTR/L. An occupational thera- another by means of the written word. pist who has met the requirements to To qualify legally as libel, written com- practice in states with licensure laws munication must intentionally impugn governing occupational therapy. Usu- the reputation of another person and ally, licensed therapists have been cer- be both malicious and demonstrably tified by the National Board for Certifi- false. cation in Occupational Therapy as a Liberty Mutual elbow Boston arm. registered occupational therapist libidinous (lı˘-bı˘dЈı˘-nu˘s) [L. libidinosus, (OTR). Some state governments, as part pert. to desire] Characterized by sexual of their licensure statutes, permit use of desires. the OTR/L or LOTR designations. libido (lı˘-bı¯Јdo¯, −be¯Јdo¯) [L., desire] licensing, compulsory A law granting a short 1. The sexual drive, conscious or uncon- government access to patented drugs standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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and other intellectual property before lines called “Wickham’s striae.” Typi- the patent formally expires. Drug com- cally, the rash persists for 1 to 2 years panies have opposed compulsory licens- and then spontaneously improves, al- ing on the grounds that it limits the fi- though about one in five patients will nancial value of patent holding. Some suffer a recurrence. SYN: lichen ruber nations have sought obligatory access to planus. SEE: illus. drugs, or their generic copies, to limit pharmaceutical costs or address na- tional health emergencies. licensure (lı¯Јse˘n-shu˘r) In the health care professions, the granting of permis- sion—official, legal, or both—to per- form professional actions that may not be legally performed by those who do not have such permission. Qualification for a license in health care is usually de- termined by an official body represent- ing the state or federal government. individual l. In the health care pro- fession, licensure of an individual to perform certain medical actions. LICHEN PLANUS institutional l. In the health care in- ETIOLOGY: The cause of the rash is dustry, the authorization of hospitals, not known, but it is occasionally asso- clinics, or corporations to provide spe- ciated with the use of certain chemicals cific forms of care. (e.g., photoprocessing compounds, gold) mandatory l. Licensure that regu- or medications (e.g., beta blockers, diu- lates the practice of a profession such as retics, nonsteroidal anti-inflammatory nursing or medicine by requiring com- drugs). pliance with the licensing statute if an TREATMENT: Corticosteroids, ap- individual engages in activities defined plied topically, taken orally, or injected within the scope of that profession. into the lesions, often are effective. multistate nurse l. In the U.S., au- l. ruber moniliformis Large verru- thority or permission to practice nurs- cous lesions of lichen planus arranged ing in several states, granted after mak- as the beads in a necklace. ing a single application. l. ruber planus Lichen planus. Ј licentiate (lı¯-se˘n she¯-a˘t) 1. An individ- l. sclerosus et atrophicus A chronic, ual who practices a profession by the au- atrophic skin disorder marked by the thority granted by a license. 2. In some appearance of discrete, flat-topped, countries, a medical practitioner who white papules, which may coalesce and has no medical degree. degenerate. The skin affected by the Ј lichen (lı¯ ke˘n) [Gr. leichen, lichen] rash, which occurs most often on the 1. Any form of papular skin disease; vulva, is often thin, shiny, and scarred. usually denoting lichen planus. 2. In Although this condition is not consid- botany, any one of numerous plants con- ered precancerous, squamous cell car- sisting of a fungus growing symbioti- cinomas arise in 1% to 5% of cases. cally with certain algae. They form SYMPTOMS: Itching of the vulva, characteristic scaly or branching which may be intractable, is the most growths on rocks or barks of trees. common complaint. myxedematous l. Generalized erup- TREATMENT: Potent topical cortico- tion of asymptomatic nodules caused by steroids produce remission, but not mucinous deposits in the upper layers of cure, in the great majority of patients. the skin and in vessels and organs. SYN: vulvar dystrophy. l. nitidus A rare skin condition char- l. scrofulosus An eruption of tiny acterized by small, chronic, asympto- punctate reddish-brown papules ar- matic papules that are usually pink and ranged in circles or groups in young per- are usually located only on the penis, sons with tuberculosis. The lesions are abdomen, and flexor surfaces of the el- caused by the spread of the tubercle ba- bows and palms. cilli through the blood to the skin. l. pilaris Lichen spinulosus. l. simplex chronicus An itching pap- l. planopilaris A form of lichen ular eruption that is circumscribed and planus in which white shiny follicular located on skin that has become thick- papules are present along with the ened and pigmented as a result of usual plane papules. scratching. SEE: illus.; neurodermatitis l. planus An inflammatory rash for illus. marked by the presence of itchy, red to l. spinulosus A form of lichen with a violet, polygon-shaped papules, which spine developing in each follicle. SYN: l. typically appear on the scalp, in the oral pilaris; keratosis pilaris. cavity, or on the limbs. The papules may l. striatus A papular eruption usu- short merge into plaques crisscrossed by faint ally seen on one extremity of a child. It standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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lien (lı¯Јe˘n) [L.] The spleen. lienal (lı¯-e¯Јna˘l) [L. lien, spleen] Splenic. lienitis (lı¯Љe˘-nı¯Јtı˘s) [ЉϩGr. itis, inflam- mation] Splenitis. lienocele (lı¯-e¯Јno¯-se¯l) [ЉϩGr. kele, tu- mor, swelling] Splenocele. lienomalacia (lı¯-e¯Љno¯-ma˘-la¯Јshe¯-a˘) [Љϩ Gr. malakia, softening] Splenomalacia. lienomyelomalacia (lı¯-e¯Љno¯-mı¯Љe˘l-o¯-ma˘- la¯Јshe¯-a˘) [ЉϩЉϩmalakia, soften- ing] Softening of the spleen and bone marrow. lienopancreatic (lı¯-e¯Љno¯-pa˘nЉkre¯-a˘tЈ˘k)ı [Љ LICHEN SIMPLEX CHRONICUS ϩ Gr. pankreas, pancreas] Relating to the spleen and pancreas. Љ Ј Љϩ is arranged in linear groups and con- lienorenal (lı¯-e¯ no¯-re¯ na˘l) [ renalis, sists of pink papules. The disease, pert. to kidney] Relating to the spleen though self-limiting, may last for a year and kidney. or longer. life (lı¯f) [AS.] 1. The capability of using l. tropicus A form of lichen with red- metabolic or biochemical processes to ness and inflammatory reaction of the grow, reproduce, and adapt to the en- skin. SYN: miliaria. vironment. 2. The time between the lichenification (lı¯-ke˘nЉı˘-fı˘-ka¯Јshu˘n) [Gr. birth or inception and the death of an leichen, lichen, ϩ L. facere, to make] organism. The life of an organism be- 1. Cutaneous thickening and hardening gins at conception and ends at death; from continued irritation. 2. The chang- however, for legal and other reasons the ing of an eruption into one resembling a definition of when life begins and death lichen. occurs has been subject to a variety of lichenoid (lı¯Јke˘n-oyd) [Љϩeidos, form, interpretations. SEE: death. 3. The sum shape] Resembling lichen. total of those properties that distin- Lichtheim’s syndrome (lı˘ktЈhı¯mz) [Lud- guish living things (animals or plants) wig Lichtheim, Ger. physician, 1845– from nonliving inorganic chemical mat- 1928] Subacute combined degenera- ter or dead organic matter. tion of the spinal cord associated with l. expectancy The number of years pernicious anemia. that an average person of a given age licorice (lı˘kЈe˘r-ı˘s, −e˘r-ı˘sh) [ME.] A dried may be expected to live. Numerous fac- root of Glycyrrhiza glabra used as a fla- tors influence life expectancy, including voring agent, demulcent, and mild ex- habits (e.g., smoking); chronic illnesses pectorant. Glycyrrhiza is prepared from (e.g., congestive heart failure, end-stage licorice. Ingestion of large amounts of renal disease, or cancers); gender licorice can cause salt retention, excess (women live longer than men); and so- potassium loss in the urine, and ele- cioeconomic status. In the U.S., the av- vated blood pressure. SEE: glycyrrhiza. erage life expectancy at birth is about 78 lid [ME.] An eyelid. years. SEE: tables; years of life lost. lidocaine (lı¯Јdo¯-ka¯n) A local anesthetic l. extension The prolongation of life drug. with healthful practices (e.g., regular l. hydrochloride A local anesthetic exercise, balanced diet, abstaining from also used intravenously to treat certain tobacco, and limiting consumption of al- cardiac arrhythmias, esp. ventricular cohol). SYN: age retardation. dysrhythmias. l. satisfaction A person’s attitudes lie, transverse A position of the fetus in about life (e.g., morale or relative well- utero in which the long axis of the fetus being). It is sometimes used as a syn- is across the long axis of the mother. onym for “successful aging.” SEE: presentation for illus. l. satisfaction index ABBR: LSI. A Lieberku¨hn crypt (le¯Јbe˘r-ke¯n) [Johann self-reporting instrument to measure N. Lieberku¨hn, Ger. anatomist, 1711– personal fulfillment or contentment, 1756] One of the simple tubular glands esp. with one’s social relationships, oc- present in the intestinal mucosa. In the cupation, maturation, or aging. A total small intestine the crypts open between of five rating scales are used. the bases of the villi, and their epithe- l. span The maximal obtainable age lium includes absorptive cells that pro- by a member of a species. duce digestive enzymes, enteroendo- l. table A statistical portrait of the crine cells that secrete hormones, goblet life expectancy of individuals in a pop- cells that produce mucus, and Paneth ulation, based on known mortality data cells that secrete lysozyme. In the large for different ages, races, and sexes. intestine the crypts open to the mucosal life care retirement community ABBR: surface and secrete mucus. SYN: intes- LCRC. A residential facility, typically tinal glands; Lieberku¨hn’s glands. for older adults, that provides several short lie detector polygraph levels of supervision and access to reg- standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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Expectation of Life in Years, by Race, Sex, and Age: 1996 White Black Age in 1990 (years) Male Female Male Female Birth 73.9 79.7 66.1 72.2 5 69.5 75.2 62.4 70.3 10 64.5 70.2 57.5 65.4 15 59.6 65.3 52.6 60.5 20 54.9 60.4 48.0 55.7 25 50.2 55.6 43.7 50.9 30 45.6 50.7 39.4 46.2 35 40.9 45.9 35.1 41.6 40 36.4 41.1 31.5 37.1 45 31.9 36.4 27.1 32.8 50 27.5 31.7 23.4 28.5 55 23.3 27.3 19.9 24.5 60 19.4 23.0 16.7 20.7 65 15.8 19.1 13.9 17.2 70 12.6 15.4 11.2 13.9 75 9.8 12.0 9.0 11.2 80 7.3 8.9 7.0 8.5 85 and over 5.3 6.3 5.3 6.2

SOURCE: Adapted from U.S. Bureau of the Census: Statistical Abstract of the United States: 1999, 119th edition. Washington, DC, 1999.

Expectation of Life at Birth, 1970 to 1997, and Projections, 1995 to 2010* Total White Black and Other Year Male Female Male Female Male Female 1970 67.1 74.7 68.0 75.6 61.3 69.4 1975 68.8 76.6 69.5 77.3 63.7 72.4 1980 70.0 77.4 70.7 78.1 65.3 73.6 1981 70.4 77.8 71.1 78.4 66.2 74.4 1982 70.8 78.1 71.5 78.7 66.8 74.9 1983 71.0 78.1 71.6 78.7 67.0 74.7 1984 71.1 78.2 71.8 78.7 67.2 74.9 1985 71.1 78.2 71.8 78.7 67.0 74.8 1986 71.2 78.2 71.9 78.8 66.8 74.9 1987 71.4 78.3 72.1 78.9 66.9 75.0 1988 71.4 78.3 72.2 78.9 66.7 74.8 1989 71.7 78.5 72.5 79.2 66.7 74.9 1990 71.8 78.8 72.7 79.4 67.0 75.2 1991 72.0 78.9 72.9 79.6 67.3 75.5 1992 72.3 79.1 73.2 79.8 67.7 75.7 1993 72.2 78.8 73.1 79.5 67.4 75.5 1994 72.3 79.0 73.2 79.6 67.5 75.8 1995 72.5 78.9 73.4 79.6 67.9 75.7 1996 73.0 79.0 73.8 79.6 68.9 76.1 1997 73.6 79.2 74.3 73.9 (NA) (NA) Projection†: 1995 72.5 79.3 73.6 80.1 (NA) (NA) 2000 73.0 79.7 74.2 80.5 (NA) (NA) 2005 73.5 80.2 74.7 81.0 (NA) (NA) 2010 74.1 80.6 75.5 81.6 (NA) (NA)

* In years. Excludes deaths of nonresidents of the United States. † Based on middle mortality assumptions. ‡NAϭ Not available. SOURCE: Adapted from U.S. Bureau of the Census: Statistical Abstract of the United States: short 1999, 119th edition. Washington, DC, 1999. standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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istered health care professionals. basic life s. ABBR: BLS. 1. A level LCRCs are typically at a location that of provider trained in CPR and emer- combines independent apartments with gency care. 2. A level of out-of-hospital assisted living residences and skilled emergency service. 3. Cardiopulmo- nursing facilities. Residents relocate nary resuscitation and the use of an au- from one level of care to another, de- tomatic external defibrillator. SEE: de- pending on their immediate needs for fibrillation; defibrillator. assistance. For example, an older basic cardiac l.s. ABBR: BLS. The woman who undergoes a knee replace- phase of cardiopulmonary resuscitation ment procedure may spend several (CPR) and emergency cardiac care that weeks recuperating and undergoing re- either (1) prevents circulatory or respi- habilitation in the nursing facility be- ratory arrest or insufficiency by prompt fore returning to semi-independent recognition and early intervention or by apartment living (in which meals are early entry into the emergency care sys- provided in a common cafeteria) or to in- tem or both; or (2) externally supports dependent housing (e.g., with a healthy the circulation and respiration of a pa- spouse). tient in cardiac arrest through CPR. life review therapy A type of insight-ori- When cardiac or respiratory arrest oc- ented therapy that focuses on conflict curs, BLS should be initiated by anyone resolution. It is usually conducted with present who is familiar with CPR. SEE: people near the end of their lives and is advanced cardiac life support; bag- designed to allow them to come to terms valve-mask resuscitator; cardiopulmo- with conflict with others, gain meaning nary resuscitation; emergency cardiac from their lives, and die peacefully. care; Heimlich maneuver. life skills Any personal ability that helps prehospital trauma l.s. ABBR: an individual to cope with people, prob- PHTLS. A continuing education course lems, situational changes, or stress. Life developed by the National Association skills include adaptability, creativity, of Emergency Medical Technicians, de- critical thinking, decision making; emo- signed to improve the assessment and tional intelligence, listening, negotia- management of trauma patients in the tion, relationship building, and self- field. awareness. withholding l.s. Removal of or not lifestyle A person’s pattern of living and giving medical interventions during behavior, esp. as distinguished from the end-of-life care, with the expectation behavior patterns or life choices of oth- that the patient will die as a result. ers. SEE: lifestyle, sedentary. lifestyle, sedentary Reports a habit of life life support The use of any technique, that is characterized by a low physical therapy, or device to assist in sustaining activity level. SEE: Nursing Diagnoses life. Appendix. advanced cardiac l.s. ABBR: ACLS. lifestyle redesign A comprehensive cus- 1. The resuscitation of dying patients; a tomized program of community-based process that involves management of the occupational therapy, intended to im- airway, reestablishment of breathing, prove daily work, recreation, and health and the restoration of spontaneous heart practices as well as the social interac- rhythm, blood pressure, and organ per- tions of independently living people, fusion. ACLS begins with the recogni- esp. older adults. tion of cardiac or respiratory emergen- life-sustaining therapy Therapy of a crit- cies, and includes basic life support ically ill patient that, if discontinued, (opening the airway and providing chest would cause the patient to die. SEE: life compressions), defibrillation, endotra- support. cheal intubation, oxygenation and ven- Li-Fraumeni syndrome (le¯Јfro¯-me¯-ne¯) tilation, the use of medications that re- [Fredrick Li, epidemiologist; Joseph store normal cardiac rhythms and Fraumeni, epidemiologist] Inherited cardiac output, cardiac pacing (when condition in which individuals develop needed), and post-resuscitation care. It multiple primary tumors, including may begin in the out-of-hospital setting, breast cancer, osteosarcoma, chondro- or take place in the hospital. 2. A train- sarcoma, soft tissue sarcoma, brain tu- ing course in resuscitation techniques mors, adrenal cortex tumors, etc. Mu- for health care providers offered by the tations of the p53 gene on chromosome American Heart Association. SEE: basic 17 are responsible for this disease. cardiac life support; cardiopulmonary lift (lı˘ft) [ME. liften] 1. To raise or ele- resuscitation; emergency cardiac care. vate. 2. A material used to equalize the advanced trauma l.s. ABBR: ATLS. length of a shortened side of the body 1. Treatment measures needed to man- with the unshortened side. age a critically injured patient. 2. A ligament (lı˘gЈa˘-me˘nt) [L. ligamentum, a course offered by the American College band] 1. A band or sheet of strong fi- of Surgeons designed to prepare physi- brous connective tissue connecting the cians to manage critical trauma pa- articular ends of bones, binding them short tients. together to limit motion. 2. A thickened standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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portion or fold of peritoneum or mesen- of the bodies of the vertebrae and the tery that supports a visceral organ or intervertebral discs. connects it to another viscus. 3. A band anterior tibiofibular l. A broad liga- of fibrous connective tissue connecting ment located on the anterior half of the bones, cartilages, and other structures distal fibula, superior to the lateral mal- and serving to support or attach fascia leolus, that binds the fibula to the tibia. or muscles. 4. A cordlike structure rep- The anterior tibiofibular ligament is resenting the vestigial remains of a fetal part of the distal ankle syndesmosis. blood vessel. SEE: crural interosseous l.; posterior ti- accessory l. A ligament that supple- biofibular l. ments another, esp. one on the lateral anterior tibiotalar l. Ligament of the surface of a joint. This type of ligament ankle that connects the anteromedial lies outside of and independent of the portion of the talus to the anterior por- capsule of a joint. tion of the medial malleolus, preventing acromioclavicular l. The ligament anterior displacement of the talus supporting the acromioclavicular joint; within the mortise, esp. when the ankle it joins the acromial process of the scap- is plantar flexed. The anterior tibiotalar ula and the distal end of the clavicle ligament is categorized as part of the and, in combination with the coracocla- ankle’s deltoid ligament complex. SEE: vicular ligaments, holds the clavicle deltoid l. down. apical l. A single median ligament ex- alar l. One of a pair of short round lig- tending from the odontoid process to the aments extending up from the sides of occipital bone. the dens, through the foramen of the at- arcuate l. The lateral, medial, and ex- las, and attaching to the sides of the fo- terior ligaments that extend from the ramen magnum of the skull. They limit 12th rib to the transverse process of the side flexion and rotation of the head in first lumbar vertebra, to which the dia- relation to the vertebral column phragm is attached. annular l. A circular ligament, esp. arterial l. A fibrous cord extending one enclosing a head or radius or one from the pulmonary artery to the arch holding the footplate of the stapes in the of the aorta, the remains of the ductus oval window. arteriosus of the fetus. anococcygeal l. A band of fibrous tis- auricular l. The anterior, posterior, sue joining the tip of the coccyx with the and superior auricular ligaments unit- external anal sphincter. ing the external ear to the temporal anterior cruciate l. ABBR: ACL. The bone. ligament of the knee that originates on broad l. of liver A wide, sickle- the anteromedial portion of the tibia’s shaped fold of peritoneum, attached to the lower surface of the diaphragm, the intercondylar eminence, passes later- internal surface of the right rectus ab- ally to the posterior cruciate ligament, dominis muscle, and the convex surface and attaches on the medial portion of of the liver. the posterior aspect of the lateral fem- broad l. of uterus The folds of peri- oral condyle. The ACL prevents anterior toneum attached to lateral borders of displacement of the tibia relative to the the uterus from insertion of the fallo- femur, internal and external rotation of pian tube above to the pelvic wall. They the tibia on the femur, and hyperexten- consist of two layers between which are sion of the tibiofemoral joint. found the remnants of the wolffian SYMPTOMS: A torn ACL causes pain ducts, cellular tissues, and the major and functional instability in the knee. blood vessels of the pelvis. TREATMENT: Arthroscopic surgery is calcaneofibular l. ABBR: CFL. An usually necessary to repair torn ACLs. extracapsular ligament of the lateral Sometimes open surgery, or arthro- ankle joint. The calcaneofibular liga- tomy, is necessary for particularly com- ment originates from the inferior apex plex repairs. of the lateral malleolus and courses at anterior talofibular l. The ligament of approximately a 133Њ angle to attach to the ankle that connects the lateral talus the calcaneus. It is the primary re- and fibular malleolus, preventing ante- straint against talar inversion when the rior displacement of the talus in the ankle is in its neutral position. mortise. This ligament is injured with capsular l. Heavy fibrous structures, an excessive inversion and plantar flex- lined with synovial membrane and sur- ion motion (supination) and is the most rounding articulations. commonly injured ligament of the an- check l. A ligament that restrains the kle. motion of a joint, esp. the lateral odon- anterior longitudinal ligament The toid ligaments. thick wide connective tissue band run- collateral l. One of the ligaments that ning along the front of the entire verte- provide medial and lateral stability to bral column. The anterior longitudinal joints. They include the medial (ulnar) short ligament attaches to the front and sides and lateral (radial) collateral ligaments standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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at the elbow, the medial (tibial) and lat- arthrotomy, is necessary for particu- eral (fibular) collateral ligaments at the larly complex repairs. knee, the medial (deltoid) and lateral cruciform l. Cruciate ligament. collateral ligaments at the ankle, and crural l. Inguinal ligament. the collateral ligaments of the fingers. crural interosseous l. A thickening of conoid l. The posterior and inner por- the interosseous membrane as it ex- tion of the coracoclavicular ligament. tends into the space between the distal coracoacromial l. The broad triangu- tibia and fibula, allowing only a slight lar ligament attached to the outer edge amount of spreading between the two of the coracoid process of the scapula bones. SEE: anterior tibiofibular l.; pos- and the tip of the acromion. terior tibiofibular l. coracoclavicular l. The ligament unit- deltoid l. The collective term for the ing the clavicle and coracoid process of medial ankle ligaments, formed by the the scapula. It has two parts, the conoid anterior tibiotalar, tibionavicular, tibio- and the trapezoid ligaments. calcaneal, and posterior tibiotalar liga- coracohumeral l. The broad ligament ments. As a group, the deltoid ligament connecting the coracoid process of the limits eversion and rotation of the talus scapula to the greater tubercle of the within the ankle mortise. SEE: illus. humerus. coronary l. of liver A fold of perito- neum extending from the posterior edge of the liver to the diaphragm. costocoracoid l. The ligament joining the first rib and coracoid process of the Anterior tibiotalar lig. scapula. costotransverse l. The ligaments Tibionavicular lig. uniting the ribs with the transverse pro- Tibiocalcaneal lig. cesses of the vertebrae. costovertebral l. Ligaments uniting Posterior tibiotalar lig. the ribs and vertebrae. cricopharyngeal l. A ligamentous bundle between the upper and posterior border of the cricoid cartilage and the anterior wall of the pharynx. DELTOID LIGAMENTS cricothyroid l. The ligament uniting cricoid and thyroid cartilages and the lo- Surface anatomy cation for the horizontal incision (called coniotomy) to prevent choking. dentate l. Lateral extensions of the spinal pia mater between the nerve cricotracheal l. The ligamentous roots; they fuse with the arachnoid and structure uniting the upper ring of the dura mater, and hold the spinal cord in trachea and the cricoid cartilage. SEE: place in the dural sheath. They have a cricoid cartilage. scalloped appearance as they pierce the cruciate l. 1. The ligament of the an- arachnoid to attach to the dura mater at kle passing transversely across the dor- regular intervals. sum of the foot that holds tendons of the dentoalveolar l. Periodontal l. anterior muscle group in place. 2. A falciform l. of liver A wide, sickle- cross-shaped ligament of the atlas con- shaped fold of peritoneum attached to sisting of the transverse ligament and the lower surface of the diaphragm, in- superior and inferior bands, the former ternal surface of the right rectus abdom- passing upward and attaching to the inis muscle, and convex surface of the margin of the foramen magnum, the lat- liver. ter passing downward and attaching to fundiform l. of penis The ligament the body of the atlas. 3. Either of two extending from the lower portion of the ligaments of the knee, the anterior linea alba and Scarpa’s fascia to the dor- (from the posterior femur to the anterior sum of the penis. tibia), and the posterior (from the an- gastrocolic l. The secondary attach- terior femur to posterior tibia). They ment of the greater curvature of the provide rotary stability for the knee stomach and the transverse colon and prevent displacement of the tibia. formed by the folding of the gastrocolic SYN: cruciform l. SEE: anterior cruci- mesentery to become the greater omen- ate l. tum. SYMPTOMS: A torn cruciate ligament gastrophrenic l. A fold of peritoneum causes instability and pain in the knee. between the esophageal end of the stom- The type of instability depends on which ach and the diaphragm. cruciate ligament is damaged. gastrosplenic l. The fold of visceral TREATMENT: Arthroscopic surgery is peritoneum that connects the edge of usually necessary to repair torn cruciate the stomach and the hilum of the short ligaments. Sometimes open surgery, or spleen. standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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Gimbernat’s l. SEE: Gimbernat’s lig- pectineal l. A triangular ligament ament. that extends from the medial end of the gingivodental l. The part of the peri- inguinal ligament along the pectineal odontal ligament that extends into the line of the pubis. gingiva and blends with the connective periodontal l. ABBR: PDL. The con- tissue lamina propria. nective tissue attached to the cementum glenohumeral l. One of the fibers of on the outer surface of a dental root and the coracohumeral ligament passing the osseous tissue of the alveolar pro- into the joint and inserted into the inner cess. The periodontal ligament holds and upper part of the bicipital groove. the teeth in the sockets of the bone. glenoid l. Glenoid labrum. SYN: dentoalveolar l.; alveolar perios- Henle’s l. SEE: under Henle, Fried- teum. rich G.J. Petit’s l. SEE: Petit’s ligament. hepaticoduodenal l. A fold of perito- phrenicocolic l. A fold of peritoneum neum from the transverse fissure of the joining the left colic flexure of the colon liver to the vicinity of the duodenum to the adjacent costal portion of the di- and right flexure of colon, forming the aphragm. anterior boundary of the epiploic fora- phrenicopericardial ligaments The men. connective tissue that attaches the bot- iliofemoral l. The Y-shaped bundle of tom of the fibrous pericardial sac to the fibers forming the upper and anterior top of the central tendon of the dia- portion of the capsular ligament of the phragm. When the diaphragm contracts hip joint. This ligament extends from and moves downward, the pericardial the ilium to the intertrochanteric line. sac and the heart are pulled down and SYN: Y ligament. elongated. iliopectineal l. A portion of the pelvic popliteal arcuate l. The ligament on fascia attached to the iliopectineal line the posterolateral side of the knee, ex- and to the capsular ligament of the hip tending from the head of the fibula to joint. the joint capsule. inguinal l. The ligament extending posterior longitudinal l. The contin- from the anterior superior iliac spine to uous narrow band of connective tissue the pubic tubercle. SYN: crural l.; Pou- lining the front inner surface of the en- part’s ligament. tire vertebral canal. It attaches the ver- interclavicular l. The bundle of fibers tebral bodies and intervertebral discs between the sternal ends of the clavi- and forms the smooth front wall of the cles, attached to the interclavicular vertebral foramen. notch of the sternum. posterior talofibular l. ABBR: PTL. interspinal l. The ligament extending A ligament of the lateral ankle that at- from the superior margin of a spinous taches the posterior portion of the talus, process of one vertebra to the lower and a portion of the posterolateral cal- margin of the one above. caneus, to the medial malleolus. The ischiocapsular l. In the hip, the liga- posterior talofibular ligament limits the ment extending from the ischium to the excessive dorsiflexion and inversion of ischial border of the acetabulum. the talus within the ankle mortise. Lisfranc’s l. SEE: Lisfranc’s ligament. posterior tibiofibular l. A broad liga- Mackenrodt’s l. SEE: Mackenrodt’s ment that binds the fibula to the tibia; ligament. located on the posterior half of the distal medial l. A broad ligament that con- fibula, superior to the lateral malleolus. nects the medial malleolus of the tibia The posterior tibiofibular ligament is to the tarsal bones. part of the distal ankle syndesmosis. median umbilical l. The fibrous cord SEE: anterior tibiofibular l.; crural in- extending from the apex of the bladder terosseous l. to the umbilicus. It represents the re- posterior tibiotalar l. Ligament of the mains of the urachus of the fetus. ankle that connects the posteromedial nuchal l. The upward continuation of portion of the talus to the posterior por- the supraspinous ligament, extending tion of the medial malleolus, preventing from the seventh cervical vertebra to posterior displacement of the talus the occipital bone. within the mortise, esp. when the ankle palpebral l. Two ligaments, medial is dorsiflexed. The posterior tibiotalar and lateral, extending from tarsal ligament is categorized as part of the plates of the eyelids to the frontal pro- deltoid ligament complex of the ankle. cess of the maxilla and the zygomatic SEE: deltoid l. bone, respectively. The orbicularis oculi Poupart’s l. Inguinal l. muscles attach to the medial palpebral pterygomandibular l. The ligament ligaments. between the apex of the internal ptery- patellar l. The continuation of the ten- goid plate of the sphenoid bone and the don of the quadriceps femoris muscle; it posterior extremity of the internal encloses the patella and secures it in oblique line of the mandible. short front of the knee joint. pubic arcuate l. The ligaments con- standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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necting the pubic bones at the symphy- apices of the spinous processes of the sis pubis, including anterior and supe- vertebrae. rior pubic ligaments and the arcuate suspensory l. of axilla The continu- (inferior) ligament. ation of the clavipectoral fascia down to pulmonary l. A fold of pleura that ex- attach to the axillary fascia. tends from the hilus of the lung to the suspensory l. of lens The zonula cil- base of the medial surface of the lung. iaris (ciliary zonule); the fibers holding rhomboid l. of clavicle A ligament the crystalline lens in position. extending from the tuberosity of the suspensory l. of ovary A ligament clavicle to the outer surface of the car- extending from the tubal end of the tilage of the first rib. ovary laterally to the pelvic wall. It lies Rivinus’ l. SEE: under Rivinus, Au- in the layers of the broad ligament in gust Quirinus. which the ovarian artery is found. round l. of femur The ligament of the suspensory l. of penis A triangular head of the femur that is attached to the bundle of fibrous tissue extending from anterior superior part of the fovea of the the anterior surface of the symphysis head of the femur and to the sides of pubis and adjacent structures to the pe- the acetabular notch. nis, surrounding the penis at its root be- round l. of liver A fibrous cord ex- fore merging with the deep fascia of the tending upward from the umbilicus and penis. enclosed in lower margin of the falci- sutural l. Any of the thin layers that form ligament; represents obliterated are found in a fibrous joint between left umbilical vein of the fetus. bones (e.g., the bones of the skull) and round l. of uterus The pair of liga- are united by sutures. ments attached to the uterus immedi- temporomandibular l. The thickened ately below and in front of the entrance portion of the joint capsule that passes of the fallopian tubes. Each extends lat- from the articular tubercle at the root of erally in the broad ligament to the pel- the zygomatic arch to attach to the sub- vic wall, where it passes through the in- condylar neck of the mandible. guinal ring, terminating in the labium transverse humeral l. A fibrous band majora. that bridges the bicipital groove of the sacroiliac l. Two ligaments, the ante- humerus in connecting the lesser and rior and posterior, that connect sacrum greater tuberosities. and ilium. transverse l. of atlas A ligament sacrospinous l. The ligament extend- passing over the odontoid process of the ing from the spine of the ischium to the axis. sacrum and coccyx in front of the sac- trapezoid l. The lateral portion of the rotuberous ligament. coracoclavicular ligament. sacrotuberous l. The ligament ex- triangular l. One of two ligaments, tending from the tuberosity of the is- right and left, connecting posterior por- chium to the posterior superior and in- tions of the right and left lobes of the ferior iliac spines and to the lower part liver with corresponding portions of the of the sacrum and coccyx. diaphragm. sphenomandibular l. The ligament uterorectosacral l. One of the liga- attached superiorly to the spine of the ments that arise from the sides of the sphenoid and inferiorly to the lingula of cervix and pass upward and backward, the mandible. The sphenomandibular passing around the rectum, to the sec- ligament is a key part of the temporo- ond sacral vertebra. They are enclosed mandibular joint, helps support the within the rectouterine folds, which de- weight of the mandible when the man- marcate the borders of the rectouterine dibular muscles are relaxed, and also pouch. controls and guides the swing of the uterosacral l. SEE: Petit’s ligament. mandible as it moves. venous l. of liver A solid fibrous cord spiral l. of cochlea The thickened representing the obliterated ductus ve- periosteum of the peripheral wall of the nosus of the fetus. It lies between the osseous cochlear canal. The basilar caudate and left lobes of the liver and membrane is attached to its inner sur- connects the left branch of the portal face. vein to the inferior vena cava. spring l. The interior calcaneonavic- ventricular l. of larynx The lateral ular ligament of the sole of the foot. It free margin of the quadrangular mem- joins the calacaneus to the navicular. brane. It is enclosed within and sup- stellate l. One of the anterior costo- ports the ventricular fold. vertebral ligaments. vesicouterine l. The ligament that at- stylohyoid l. A thin fibroelastic cord taches the anterior aspect of the uterus between the lesser cornu of the hyoid to the bladder. bone and the apex of the styloid process vocal l. The thickened free edges of of the temporal bone. the elastic cone extending from the thy- short supraspinal l. A ligament uniting the roid angle to the vocal processes of standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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arytenoid cartilages. They support the otide probes. Double-stranded DNA is vocal folds. denatured. Probes bind to the comple- xiphocostal l. The ligament connect- mentary strands on any denatured tar- ing the xiphoid process to the cartilage get DNA. Ligase joins the bound probes, of the eighth rib. and multiple copies of the DNA of inter- Yl.Iliofemoral ligament. est are made. In clinical practice, ligase yellow l. One of the ligaments con- chain reactions are used primarily in necting the laminae of adjacent verte- urinary (noninvasive) assays to detect brae. genital infections with chlamydia or Zagla’s l. SEE: Zagla’s ligament. gonorrhea. ligamenta (lı˘g-a˘-me˘nЈta˘) Pl. of ligamen- ligate (lı¯Јga¯t) To apply a ligature. tum. ligating module (lı¯Јga¯t-ı˘ng) In orthodon- ligamentous (lı˘gЉa˘-me˘nЈtu˘s) [L. liga- tics an appliance, typically made of mentum, band] 1. Relating to a liga- polyurethane, that fits over a bracket ment. 2. Like a ligament. and holds an archwire in place. ligamentum (lı˘gЉa˘-me˘nЈtu˘m) pl. liga- ligation (lı¯-ga¯Јshu˘n) The application of a menta [L., a band] Ligament. ligature. l. arteriosum In the adult, the cord- rubber-band l. The application of a like remnant of the fetal ductus arteri- rubber band around a superficial bit of osus between the left pulmonary artery tissue, such as an internal hemorrhoid and the arch of the aorta. Just after or an esophageal varix. Because its birth, the ductus arteriosus constricts blood supply is thereby cut off, the tis- and begins to fill with endothelial cells, sue dies and sloughs. and within a few months the ductus ar- ligature (lı˘gЈa˘-chu¯r) [L. ligatura, a bind- teriosus is completely closed. For the re- ing] 1. Process of binding or tying. 2. A mainder of one’s life, the closed duct re- band or bandage. 3. A thread or wire for mains as a connecting cord attaching tying a blood vessel or other structure the two large outflow arteries of the in order to constrict or fasten it. The heart. cord or material used may be catgut, l. flavum A ligament that binds ad- synthetic suture materials such as ny- jacent vertebral laminae to each other. lon or Dacron, polyglycolic acid, or nat- l. teres In the adult, the closed rem- ural fibers such as silk or cotton. Some- nant of the fetal umbilical vein. It runs times strips of fascia obtained from the inside the free edge of the falciform lig- patient are used as a ligature. SEE: su- ament from the underside of the umbil- ture. icus to the liver. wire l. A soft, thin wire, elastic cord, ligand (lı¯Јga˘nd, lı˘gЈa˘nd) [L. ligare, to or elastic loop used in orthodontics to bind] 1. In chemistry, an organic mol- anchor an arch wire or other dental de- ecule attached to a central metal ion by vices or to tie two structures together. multiple bonds. 2. Any chemical that light (lı¯t) [AS. lihtan, to shine] Radiant binds to a specific receptor site, e.g., on electromagnetic energy limited to a a cell membrane. 3. In immunology, a wavelength of about 400 nm (extreme small molecule bound to another chem- violet) to 770 nm (extreme red). ical group or molecule. l. adaptation Changes that occur in fas l. ABBR: FasL. A protein on the a dark-adapted eye in order for vision to surface of activated T cells that binds to occur in moderate or bright light. Prin- Fas receptors on the surface of the same cipal changes are contraction of the pu- or other T cells and triggers a series of pil and breakdown of rhodopsin. Bright events causing apoptosis. This process sunlight is 30,000 times the intensity of is involved in the activation-induced cell bright moonlight, but the eye adapts so death necessary to ensure that autore- that visual function is possible under active T cells do not attack “self-”anti- both conditions. SEE: night vision; vi- gens. sion. neuroimmunophilin l. Any of the axial l. Light with rays parallel to small molecules that can stimulate neu- each other and to the optic axis. rons to grow new axons and dendrites. cold l. Any form of light that is not They can cross the blood-brain barrier, perceptibly warm. The heat of ordinary and therefore may be used to treat neu- light rays is dissipated when they are rodegenerative diseases or central ner- passed through some medium such as vous system injuries. quartz. ligase (lı¯Јga¯s, lı˘gЈa¯s) The general term l. difference The difference between for a class of enzymes that catalyze the the two eyes with respect to sensitivity joining of the ends of two chains of DNA. to light intensity. ligase chain reaction A technique for am- diffused l. Rays broken by refraction. plifying the quantity of specific se- idioretinal l. The sensation of light quences of nucleic acid in a specimen. when there are no retinal stimuli to The patient’s DNA, or specimens produce that sensation. SYN: intrin- thought to contain pathogenic DNA, are sic l. short mixed with DNA ligase and oligonucle- intrinsic l. Idioretinal light. standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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oblique l. Light that strikes a surface tomobile if driving. If an electrical obliquely. charge is evidenced by hair standing on polarized l. Light in which waves vi- end or tingling of the skin, one should brate in one direction only. immediately squat with feet touching reflected l. Light rays that are each other and hands clasped around thrown back by an illuminated object the knees. No part of the rest of the body such as a mirror. should touch the ground. It is important refracted l. Rays bent from their to be aware that, when lightning original course. strikes, the charge may be as much as l. sense One of the three parts of vi- 100 million volts. Trees conduct elec- sual function, the other parts being tricity better than air, and metal and color sense and form sense. It is tested water conduct better than trees. Light- by visual field examination. SEE: color ning will strike the tallest object. sense; form sense. light reaction That stage of photosynthe- l. therapy Phototherapy. sis in which photons are captured by transmitted l. Light that passes cells and used to supply the energy through an object. needed to synthesize carbohydrates. white l. Light that contains all of the Chlorophyll is the light-trapping mole- visible wavelengths of light. cule of most plants. Bacteriochlorophyll Wood’s l. SEE: Wood’s rays. is a related compound used by bacteria lightening [AS. leohte, not heavy] The to capture the energy supplied by light. descent of the presenting part of the fe- light sleep A colloquial term for the first tus into the pelvis. This often occurs 2 stage of non–rapid eye movement to 3 weeks before the first stage of labor (NREM) sleep. It is sometimes also ap- begins. It may not occur in multiparas plied to the second stage of NREM until active labor begins. SYN: engage- sleep. ment. SEE: labor. light unit A foot-candle, or the amount of light-headedness The feeling of dizziness light 1 ft from a standard candle. The or of being about to faint; a nonspecific ideal amount of light required for work symptom of many conditions, including varies with the specific type of work be- for example, anemia, anxiety, cardiac ing done. The term foot-candle took the rhythm disturbances, fever, low blood place of candle power, but light inten- pressure, many infections, and some sity in the International System of drugs. Units is indicated by lumen. SEE: can- lightning The discharge of atmospheric dela; lumen. electricity from cloud to cloud or from lightwand (lı¯t’wa˘nd) [” ϩ ME. slender cloud to earth. About 100 lightning stick] A stylet that transilluminates strokes hit the earth every second. In the soft tissues of the neck. It is used in the U.S. each year, about 500 to 1000 endotracheal intubation. people are struck by lightning; between lignan (lı˘gЈna˘n) A steroid-like chemical 150 and 300 of these die as a result of found in flaxseed and related plants being struck. that may be beneficial in the manage- lightning safety rules Any of the rules ment of hormone-sensitive illnesses. that, if followed, could reduce the deaths SEE: phytoestrogen. that occur from electrocution due to lignin (lı˘gЈnı˘n) A polymer present in lightning. During a lightning storm one plants that combines with cellulose to should remain indoors but not near form cell walls. It is one of the compo- open doors, fireplaces, radiators, or ap- nents of dietary fiber in fruits and veg- pliances. Plug-in electric equipment etables. Lignin is not digestible at all by (e.g., hair dryers, electric toothbrushes, the bacterial enzymes in the colon. or electric razors) should not be used. lignoceric acid (lı˘gЉno¯-se˘rЈı˘k) A satu- One should not take laundry off clothes- rated, naturally occurring fatty acid, lines or work on fences, computers or C24H48O2, present in certain foods, in- word processors, telephones or tele- cluding peanuts. phone lines, power lines, pipelines, or likelihood ratio (lı¯kЈle¯-hoodЉ) ABBR: LR. structural steel construction, or use A statistical tool used to help determine metal objects such as fishing rods or golf the usefulness of a diagnostic test for in- clubs. When outdoors, if lightning is cluding or excluding a particular dis- spotted nearby, one should plan an ease. An LR ϭ 1 suggests that the test evacuation to a safe, substantial build- ordered neither helps to diagnose the ing or an enclosed metal vehicle. Hill- disease in question nor helps to rule it tops should be avoided. In a forest, shel- out. Higher LRs increase the probability ter should be sought in a low area under that the disease will be present; LRs a thick growth of small trees. Open Ͻ1.0 decrease the probability that the spaces, wire fences, metal clotheslines, disease is present. exposed sheds, and all electrically con- A positive LR can be thought of as the ductive elevated objects should be probability that someone with a sus- avoided. People should get out of water pected condition will, accurately, have a short and off small boats but stay in an au- positive test result, divided by the prob- standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh limb 1342 limit base of rh

ability that a healthy person will, inac- the alveolar process of the mandible. curately, test positive for the disease. 2. The lower free edge of the alveolar Mathematically this can be represented process of the maxilla. SYN: arcus al- by the following equation: LRϩϭsen- veolaris maxillae. sitivity of the test/ (1Ϫ specificity of the l. conjunctivae The edge of the con- test). A negative LR is the probability junctiva overlapping the cornea. that a sick person will fail to be detected l. corneae The edge of the cornea by the test, divided by the probability where it unites with the sclera. that a healthy person will be accurately corneoscleral l. In the eye, a transi- shown by the test to have no sign of dis- tional dome 1 or 2 mm wide where the ease. Mathematically: LRϪϭ(1 Ϫ sen- cornea joins the sclera and conjunctiva. sitivity of the test) / specificity of the l. laminae spiralis osseae A thick- test. ening of the periosteum of the osseous limb (lı˘m) [AS. lim] 1. An arm or leg. spiral lamina of the cochlea to which the 2. An extremity. 3. A limblike extension tectorial membrane is attached. of a structure. l. palpebrales anteriores The ante- anacrotic l. The ascending portion of rior margin of the free edge of the eye- the pulse wave. lids from which the cilia or eyelashes anterior l. of internal capsule The grow. lenticulocaudate portion that lies be- l. palpebrales posteriores The pos- tween the lenticular and caudate nuclei. terior margin of the free edge of the eye- ascending l. of renal tubule The por- lids; the region of transition of skin to tion of the tubule between the bend in conjunctival mucous membrane. Henle’s loop and the distal convoluted l. sphenoidalis Ridge on the anterior tubule. portion of upper surface of sphenoid catacrotic l. The descending portion bone. of the pulse wave. lime (lı¯m) [AS. lim, glue] Calcium oxide, descending l. of renal tubule The CaO. portion of the tubule between the prox- soda l. A white granular substance imal convoluted tubule and the bend in consisting of a mixture of calcium hy- Henle’s loop. droxide and sodium hydroxide or potas- pectoral l. The upper extremity. sium hydroxide, or both. It is used to ab- pelvic l. The lower extremity. sorb carbon dioxide and as an absorbing phantom l. SEE: sensation, phan- compound in anesthesia. tom. lime [Fr.] 1. The fruit of Citrus auranti- l. replantation The surgical reattach- folia, which contains vitamin C. 2. The ment of a traumatically amputated limb yellowish green fruit of a lime with an or part. acid pulp used as a preservative, flavor- thoracic l. The upper extremity. ing agent, and high in vitamin C. limbic (lı˘mЈbı˘k) [L. limbus, border] limen (lı¯Јme˘n) pl. limina [L.] Entrance; Pert. to a limbus or border. SYN: mar- threshold. ginal. l. nasi The boundary line between limbic system A group of brain struc- the bony and cartilaginous portion of tures, including the hippocampus, the nasal cavity. It is also at this point amygdala, dentate gyrus, cingulate gy- that the nasal cavity proper and the ves- rus, gyrus fornicatus, the archicortex, tibule of the nose meet. and their interconnections and connec- l. of insula The portion of the cortex tions with the hypothalamus, septal of the brain that provides a threshold to area, and a medial area of the mesen- the insula. The middle cerebral artery cephalic tegmentum. The system is ac- passes over this threshold to extend to tivated by motivated behavior and the insula. arousal, and it influences the endocrine limestone A rock formed of organic fossil glands and autonomic nervous system. remains of shells, composed mostly of SEE: illus. calcium carbonate. SEE: lime. limb perfusion A method for concentrat- liminal (lı˘mЈı˘-na˘l) [L. limen, threshold] ing a dose of chemotherapy in an arm or Hardly perceptible; relating to a thresh- leg affected by cancer. Large blood ves- old as of consciousness or vision. sels near the tumor are cannulated, the limit (lı˘mЈı˘t) 1. A boundary. 2. A point or limb is wrapped in a tourniquet, and line beyond which something cannot or chemotherapy is circulated into the may not progress. limb. Isolated limb perfusion has been acceptance l. In radiology, the range used to treat melanomas or sarcomas. of images within the diagnostic range of SYN: isolated limb perfusion. quality (i.e., density, contrast, detail). limb reduction defect A congenital mal- assimilation l. The amount of carbo- formation in which one or more limbs hydrate that can be absorbed or in- develop incompletely or not at all. gested without causing glycosuria. limbus (lı˘mЈbu˘s) pl. limbi [L., border] audibility l. The highest and the low- The edge or border of a part. est frequencies of sound that can be de- short l. alveolaris 1. The upper free edge of tected by the human ear. The lower standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh limit 1343 limulus amebocyte lysate test base of rh

THE LIMBIC SYSTEM OF THE BRAIN

limit is approx. 8 to 16 Hz and the upper limitation (lı˘mЉı˘-ta¯Јshu˘n) The condition limit is approx. 12 to 20,000 Hz. of being limited. l. of detection The smallest amount activity l. Functional limitation. of an analyte that can be detected by an functional l. In rehabilitation sci- analytical system. ence, any restriction in the performance elastic l. The extent to which some- of activities resulting from disease, in- thing may be stretched or bent and still jury, or environmental restrictions. be able to return to its original shape. SYN: activity limitation; disability. l. of flocculation The amount of a l. of motion The restriction of move- toxin or toxoid that causes the most ment or range of motion of a part or rapid flocculation when combined with joint, esp. that imposed by disease or its antitoxin. trauma to joints and soft tissues. Hayflick’s l. SEE: Hayflick’s limit. limited-service provider Health care pro- l. of perception The smallest stimu- viders or institutions, such as outpa- lus that can be perceived by any of tient surgery centers or facilities, that the senses: e.g., the faintest light, provide care to a market niche, i.e., to the smallest amount of pressure, the those individuals with a limited number softest sound, the most dilute flavor, of diseases or conditions. etc. limnology (lı˘m-no˘lЈo¯-je¯) [Gr. limne, pool, l. of quantitation ABBR: LOQ. The ϩ logos, study] The scientific study of smallest amount of analyte that can be fresh water in the environment (i.e., measured with stated and acceptable potability, pH, degree of pollution, min- imprecision and inaccuracy e.g., the eral content, and variation with sea- smallest number of viral particles that sonal and climatic changes). can be detected in a milliliter of blood. limonene (lı¯mЈo¯-ne¯n) An essential oil de- SEE: l. of detection; sensitivity. rived from orange or lemon peel. It is quantum l. The minimum wave- used as a flavoring agent in cough syr- length present in the spectrum pro- ups. duced by x-rays. limp To walk with abnormal, jerky move- ventilator l. A secondary ventilator ments. alarm or stop mechanism that prevents limulus amebocyte lysate test (lı˘mЈu¯- a specific variable from exceeding a pre- lu˘s) ABBR: LAL test. A test used to de- set parameter. tect minute quantities of bacterial en- limitans (lı˘mЈı˘-ta˘ns) [L. limitare, to dotoxins and to test for pyrogens in limit] 1. A term used in conjunction various materials; it is also used to de- with other words to denote limiting. tect septicemia due to gram-negative short 2. Membrane limitans. bacteria. Limulus amebocyte lysate is standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh LINAC 1344 line base of rh

formed from the lysed circulating ame- the center of the external auditory me- bocytes of the horseshoe crab (Limulus atus. polyphemus). cement l. The refractile boundary of LINAC linear accelerator. an osteon in compact bone. lincture, linctus (lı˘nkЈtu¯r, −tu˘s) [L. linc- central l. A venous access device in- tus, a licking] A thick, sweet, syrupy serted into and kept in the vena cava, medicinal preparation given for its ef- innominate, or subclavian veins. It is fect on the throat, usually sipped but used to infuse fluids and medicines, or may be licked or sucked as with a throat for gaining access to the heart to mea- lozenge. sure pressures in the venous circula- lindane (lı˘nЈda¯n) Gamma benzene hex- tion. Keeping the line open permits achloride. later venous access when the veins Lindau’s disease (lı˘nЈdowz) [Arvid Lin- might be collapsed and difficult to enter. dau, Swedish pathologist, 1892–1958] SEE: catheter, central venous. Lindau–von Hippel disease. central intravenous l. SEE: catheter, Lindau–von Hippel disease (lı˘nЈdow- central venous; central line. vo˘n-hı˘pЈe˘l) [Arvid Lindau; Eugen von cervical l. 1. A line of junction of ce- Hippel, Ger. ophthalmologist, 1867– mentum and enamel of a tooth. 2. A 1939] Angiomata of the retina and line on the neck of the tooth where the cysts and angiomata of the brain and gum is attached. certain visceral organs. cleavage l. Langer’s lines. line (lı¯n) [L. linea ] 1. Any long, rela- l. of demarcation A line of division tively narrow mark. 2. A boundary or between healthy and diseased tissue. outline. 3. A wrinkle. 4. In anthropom- Douglas’ l. SEE: Douglas’ line. etry or cephalometry, an imaginary line ectental l. The point of the endoder- connecting two anatomical points. This mal and ectodermal junction in the gas- is necessary to establish a plane or an trula. axis. 5. A catheter attached to a patient, epiphyseal l. A line at the junction of as an intravenous line or arterial line. the epiphysis and diaphysis of a long abdominal l. Arbitrary lines deline- bone. It is the remnant of the epiphyseal ating abdominal regions. SEE: abdomi- disk. nal regions. Feiss’ l. SEE: Feiss’ line. absorption l. A black line in the con- l. of fixation An imaginary line tinuous spectrum of light passing drawn from the subject viewed to the fo- through an absorbing medium. vea centralis. ala-tragus l. An imaginary line that gingival l. A line determined by the extends from the ala of the nose to the extent of coverage of the tooth by gin- tragus of the ear. The line is an esti- giva. The shape of the gingival line is mated point of entry for intraoral dental similar to the curvature of the cervical radiographs of the maxilla and is also line but they rarely coincide. It is also used in denture prosthodontics. called the free gingival margin. SYN: arterial l. A hemodynamic monitoring gum l.; gingival margin. system consisting of a catheter in an ar- gluteal l. Three lines—anterior, pos- tery connected to pressure tubing, a terior, and inferior—on the exterior transducer, and an electronic monitor. surface of the ilium. It is used to measure systemic blood gum l. Gingival line. pressure and to provide ease of access iliopectineal l. The bony ridge mark- for the drawing of blood (e.g., in inten- ing the brim of the pelvis. sive care, when regular monitoring of incremental l. One of the lines seen in blood gases is necessary). a microscopic section of tooth enamel. axial l. A line running in the main axis They resemble growth lines in a tree. of the body or some part of it. The axial incremental l. of Retzius Periodic line of the hand runs through the mid- dark lines seen in the enamel of a tooth dle digit; the axial line of the foot runs that represent occasional metabolic dis- through the second digit. turbances of mineralization. axillary l. Anterior, posterior, and incremental l. of von Ebner Very midaxillary lines that extend downward light lines in the dentin of a tooth that from the axilla. represent the boundary between the base l. The line from the infraorbital layers of dentin produced daily. ridge through the middle of the external inferior nuchal l. One of two curved auditory meatus to midline of occiput. ridges on the occipital bone extending basiobregmatic l. The line from ba- laterally from the exterior occipital sion to bregma. crest. SEE: superior nuchal l. Beau’s l. SEE: Beau’s lines. infraorbitomeatal l. An imaginary blue l. Lead line. line from the inferior orbital margin to Burton’s l. SEE: Burton’s line. the external auditory meatus, used for canthomeatal l. An imaginary line radiographical positioning of the skull. short extending from the canthus of the eye to intercondylar l. The transverse ridge standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh line 1345 line base of rh

joining condyles of the femur above the l. of Owen [Sir Richard Owen, Brit. intercondyloid fossa. anatomist, 1804–1892] Occasional interpupillary l. An imaginary line be- prominent growth lines or bands in the tween the centers of the eyes, used for dentin of a tooth. They provide a record radiographical positioning of the skull. of the growth of the coronal or radicular intertrochanteric l. The ridge on the dentin. posterior surface of the femur between parasternal l. The line midway be- the greater and lesser trochanters. tween the nipple and the border of the Langer’s l. SEE: Langer’s lines. sternum. lateral supracondylar l. One of two pectineal l. The line on the posterior ridges on the posterior surface of the surface of the femur extending down- distal end of the femur, formed by di- ward from the lesser trochanter. It is verging lips of the linea aspera. It is one the portion of the iliopectineal line of the proximal attachments of the vas- formed by the os pubis. tus lateralis muscle of the quadriceps. popliteal l. of femur An oblique line SEE: medial supracondylar l. on the posterior surface of the femur. lead l. An irregular dark line in the popliteal l. of tibia A line on the pos- gingival margin. The line is present in terior surface of the tibia, extending chronic lead poisoning and is caused by obliquely downward from the fibular the deposition of lead in that portion of facet on the lateral condyle to the me- the gum. SYN: blue l. dial border of the bone. lip l. The highest or lowest point the pure l. 1. The progeny of a single ho- lips reach on the teeth or gums during mozygous individual obtained by self- a broad smile. fertilization. 2. The progeny of an in- Ml.In striated muscle, the thin, dark dividual reproducing asexually by line in the center of an H band of a sar- simple fission, or by buds, runners, sto- comere. It is made of myomesin, the pro- lons, and so on. 3. The progeny of two tein that connects the thick (myosin) fil- homozygous individuals reproducing aments. SYN: M disk. sexually. mamillary l. An imaginary vertical resting l. A smooth cement line seen line through the center of the nipple. in microscopic sections that separates mammary l. An imaginary horizontal old bone from newly formed bone. line from one nipple to the other. reversal l. A cement line seen in mi- medial supracondylar l. One of two croscopic sections of bone that shows ridges on the posterior surface of the scallops and irregularites representing distal end of the femur, formed by di- earlier bone resorption. Resorption to verging lips of the linea aspera. SEE: that point occurred before the process lateral supracondylar l. reversed and new bone was formed by median l. An imaginary line joining apposition. SEE: Howship’s lacuna. any two points in the periphery of the scapular l. In anatomical descrip- median plane of the body or one of its tions, the imaginary line extending parts. downward from the lower angle of the mentomeatal l. An imaginary line scapula. from the mental point of the mandible semilunar l. Spigelian line. to the external auditory meatus, used in Shenton’s l. SEE: Shenton’s line. radiography of the skull. sight l. The line from the center of the milk l. SEE: ridge, mammary. pupil to a viewed object. mucogingival l. SEE: junction, mu- soleal l. of tibia A line on the poste- cogingival. rior surface of the tibia extending diag- mylohyoid l. A ridge on the inner sur- onally from below the tibial condyle to face of the mandible. It extends from a the medial border of the tibia. The so- point beneath the mental spine upward leus muscle and fascia are attached to and back to the ramus past the last mo- that line. lar. The mylohyoid muscle and the su- spigelian l. SEE: spigelian line. perior constrictor muscle of the pharynx sternal l. The medial line of the ster- attach to this ridge. num. nasal l. A line from the lower edge of superior nuchal l. One of two curved the ala nasi curving to the outer side of ridges on the occipital bone extending the orbicularis oris muscle. laterally from the exterior occipital oblique l. of mandible The ridge on crest. SEE: inferior nuchal l. the outer surface of the lower jaw. supraorbital l. The line across the oculozygomatic l. A line appearing forehead above the root of the exterior between the inner canthus of the eye angular process of the frontal bone. and the cheek, supposedly indicative of umbilicopubic l. The portion of me- neural disorders. dian line extending from the umbilicus orbitomeatal l. The imaginary line to the symphysis pubis. running through the mid-orbit and ex- visual l. The line that extends from ternal auditory meatus. It is commonly object to macula lutea passing through short used for radiographic positioning. the nodal point. SYN: visual axis. standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh line 1346 linguodental base of rh

Zo¨llner’s l. Parallel lines, usually A measurement of fine radiographic im- three long ones, with a series of short age detail demonstrated by the number lines drawn at regular intervals across of pairs of lead lines per millimeter that one of the lines at approx. 60 degrees. can be imaged. Similar lines are drawn across the sec- liner (lı¯nЈe˘r) Anything applied to the in- ond line at the angle of approx. 120 de- side of a hollow body or structure. grees. Short lines are drawn across the cavity l. A layer of material applied third at the same angle as on the first to a cavity preparation to protect the lines. These lines produce the optical il- pulp of the tooth. It is usually a suspen- lusion that the long lines are converging sion of zinc phosphate or calcium hy- or diverging. droxide and is used to neutralize the linea (lı˘nЈe¯-a˘) pl. lineae [L. linea, line] acidity of the base or cement material. An anatomical line. soft l. The material applied to the l. alba The white line of connective underside of a denture to provide a soft tissue in the middle of the abdomen surface contact with the oral tissues. from sternum to pubis. Some acrylic or silicone resins have l. albicantes Lines seen on the ab- been made resilient and are used as lin- domen, buttocks, and breasts, fre- ers. quently caused by pregnancy, obesity, lingua (lı˘ngЈgwa˘) pl. linguae [L.] The or prolonged adrenal cortical hormone tongue or a tonguelike structure. therapy but may occur as the result of l. frenata Ankyloglossia. abdominal distention from any cause. l. geographica Geographic tongue. l. aspera A longitudinal ridge on the l. nigra Hairy tongue. posterior surface of the middle third of l. plicata Fissured tongue. the femur. lingual (lı˘ngЈgwa˘l) [L. lingua, tongue] l. costoarticularis A line between the 1. Pert. to the tongue. 2. Tongue- sternoclavicular articulation and the shaped. SYN: linguiform. 3. In den- point of the 11th rib. tistry, pert. to the tooth surface that is l. nigra A dark line or discoloration adjacent to the tongue. of the abdomen that may be seen in lingual goiter SEE: under goiter. pregnant women during the latter part Linguatula serrata (lı˘ng-wa˘Јtoo-la˘se˘r- of term. It runs from above the umbili- a˘Јta˘) [L. “little serrated tongue”] An cus to the pubes. arthropod parasite in snakes, commonly l. semilunaris Spigelian line. known as the tongue worm. Its larvae, l. striae atrophicae Stria atrophica. nymphs, and adults occasionally infect l. terminalis A bony ridge on the in- humans. Ingested infective larvae mi- ner surface of the ilium continued on to grate to the nasal passages and may the pubis that divides the true and false cause a parasitic nasopharyngeal ob- pelvis. struction known as linguatulosis. lineage (lı˘nЈe¯-ı˘j) [ME. linage] A group of lingula (lı˘ngЈgu¯-la˘) [L., little tongue] A individuals, animals, cells, or genes that tongue-shaped process of some struc- share a common ancestor. ture. linear (lı˘nЈe¯-a˘r) [L. linea, line] Pert. to l. cerebelli A tonguelike process of or resembling a line. the cerebellum projected forward on the l. energy transfer A measure of the upper surface of the superior medullary rate of energy transfer from ionizing ra- velum. diation to soft tissue. l. of lung The projection of lung that linear accelerator A device that uses separates the cardiac notch from the in- high-frequency electromagnetic waves ferior margin of the left lung. to speed up charged particles such as l. of mandible The projection of bone electrons to high energies within a lin- that forms the medial boundary of the ear tube for use in radiation therapy, mandibular foramen and gives attach- the creation of radioisotopes, and re- ment to the sphenomandibular liga- search. ment. linear immunoglobin A disease A blis- l. of sphenoid The ridge between the tering condition that causes lesions be- body and the greater wings of the sphe- neath the epidermis, in the oral cavity, noid. and sometimes on the conjunctiva, lingulectomy (lı˘ngЉgu¯-le˘kЈto¯-me¯) [L. lin- where scars may form. The disease is gula, little tongue, ϩ Gr. ektome, ex- characterized by the presence of immu- cision] Surgical removal of the lingula noglobulin A deposits lined up along the of the upper lobe of the left lung. basement membrane of the epithelium. linguo- [L. lingua, tongue] Combining linearity (lı¯n-e¯-a˘rЈı˘-te¯) In radiography, form meaning tongue. the production of a constant amount of linguoclination (lı˘ngЈgwo¯-klı¯-na¯Јshu˘n) [Љ radiation for different combinations of ϩ clinatus, leaning] Angulation of a milliamperage and exposure time, com- tooth in its vertical axis toward the monly used as a quality management tongue. benchmark. linguodental (lı˘ngЉgwo¯-de˘nЈtl) Relating short line pairs per millimeter ABBR: lp/mm. to the tongue and teeth, such as the standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh linguopapillitis 1347 lipase base of rh

speech sound “th,” which is produced febrile diseases. Tuberculous ulcer: This with the aid of the tongue and teeth. type of ulcer is located at the inner por- linguopapillitis (lı˘ngЉgwo¯-pa˘pЉı˘-lı¯Јtı˘s) [Љ tion of the lip, close to the angle of the ϩ papilla, nipple, ϩ Gr. itis, inflam- mouth. Pathological examination is nec- mation] Small ulcers of the papillae of essary for verification. the edge of the tongue. DIAGNOSIS: Examination is consid- linguopulpal (lı˘ngЉgwo¯-pu˘lЈpa˘l) Pert. to ered to be incomplete unless the lips are the lingual and pulpal surfaces of a cav- everted to expose buccal surfaces. Blu- ity preparation. ish or purplish: This sign may appear in linguoversion (lı˘ngЉgwo¯-ve˘rЈzhu˘n) [Љϩ the aged, in those exposed to great cold, versio, a turning] Displacement of a and in hypoxemia. Dry: Mouth dryness tooth toward the tongue. may be seen in fevers or be caused by liniment (lı˘nЈı˘-me˘nt) [L. linimentum, drugs such as atropine, by thirst, or by smearing substance] A liquid vehicle mouth breathing. Fissured: This may (usually water, oil, or alcohol) contain- occur after exposure to cold, in avita- ing a medication to be rubbed on or ap- minosis, and in children with congenital plied to the skin. It may be applied by syphilis. Pale: Pallor may be seen in the friction method or on a bandage. anemia and wasting diseases, in pro- linitis (lı˘n-ı¯Јtı˘s) [Gr. linon, flax, ϩ itis, longed fever, and after a hemorrhage. inflammation] Inflammation of the lin- Rashes: These may be manifestations of ing of the stomach. typhoid fever, meningitis, or pneumo- l. plastica An infiltrating cancer of nia. Mucous patches may appear in sec- the stomach wall. SEE: leather-bottle ondary syphilis, chancre, cancer, and stomach. epithelioma. linkage In genetics, the association be- cleft l. A vertical cleft or clefts in the tween distinct genes that occupy closely upper lip. This congenital condition, re- situated loci on the same chromosome. sulting from the faulty fusion of the me- This results in an association in the in- dian nasal process and the lateral max- heritance of these genes. illary processes, is usually unilateral sex l. A genetic characteristic that is and on the left side, but may be bilat- located on the X or Y chromosome. eral. It may involve either the lip or the linseed (lı˘nЈse¯d) [AS. linsaed] Seed of upper jaw, or both, and often accompa- the common flax, Linum usitatissimum; nies cleft palate. Nongenetic factors the source of linseed oil. Linseed is used may also be responsible for causing this as a demulcent and emollient. SYN: condition. The incidence of cleft lip is flaxseed. from one in 600 to one in 1250 births. lip [AS. lippa] 1. A soft external struc- SYN: harelip. ture that forms the boundary of the double l. A redundant fold of mucous mouth or opening to the oral cavity. membrane in the mouth on either side SYN: labium oris. 2. One of the lips of of the midline of the lip. the pudendum (labia majora or minora). glenoid l. Glenoid labrum. SEE: labia; labium. 3. A liplike struc- Hapsburg l. A thick, overdeveloped ture forming the border of an opening or lower lip. groove. oral l. Upper and lower lips that sur- PATHOLOGY: Chancre: It is not un- round the mouth opening and form the usual to have the initial lesion of syph- anterior wall of the buccal cavity. ilis appear on the lip of the mouth as an tympanic l. The lower border of the indurated base with a thin secretion sulcus spiralis internus of the cochlea. and accompanied by enlargement of the vestibular l. The upper border of the submaxillary glands. Condyloma la- sulcus spiralis internus of the cochlea. tum: This appears as a mucous patch, lip- SEE: lipo-. flattened, coated with gray exudate, lipacidemia (lı˘pЉa˘s-ı˘-de¯Јme¯-a˘) [Gr. lipos, with strictly delimited area, usually at fat, ϩ L. acidus, acid, ϩ Gr. haima, the angle of the mouth. Eczema: This is blood] Excess fatty acids in the blood. characterized by dry fissures, often cov- lipaciduria (lı˘pЉa˘s-ı˘-du¯ Јre¯-a˘) [ЉϩЉϩ ered with a crust, bleeding easily, and Gr. ouron, urine] Fatty acids in the occurring on both lips. Epithelioma: urine. This may be confused with chancre. It liparocele (lı˘pЈa˘-ro¯-se¯l) [Љϩkele, tu- seldom appears before the age of 40, but mor, swelling] 1. A scrotal hernia con- there are exceptions. It may appear as taining fat. 2. A fatty tumor. a common cold sore, a painless fissure, lipase (lı˘Јpa¯s,lı¯Јpa¯s) [Љϩ−ase, enzyme] or other break of the lower lip. A crust A fat-splitting enzyme found in blood, or scab covers the lesion, leaving a raw pancreatic secretion, and tissues. Emul- surface if removed. Pain does not ap- sified fats are changed in the stomach to pear until the lesion is well advanced. It fatty acids and glycerol by gastric lip- is much more common on the lower lip ase. SEE: digestion; enzyme. than on the upper. Herpes: These le- pancreatic l. The pancreatic enzyme sions may appear on the lips in pneu- that digests fats emulsified by bile salts short monia, typhoid, common cold, and other to fatty acids and glycerol. standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh lip bumper 1348 lipodystrophy syndrome base of rh lip bumper In orthodontics a removable lipoblast (lı˘pЈo¯-bla˘st) [Љϩblastos, appliance to push the lower molars pos- germ] An immature fat cell. teriorly to create additional space for lipoblastoma (lı˘pЉo¯-bla˘s-to¯Јma˘) [ЉϩЉ the lower anterior teeth. It consists of ϩ oma, tumor] A benign tumor of the an archwire that attaches posteriorly to fatty tissue. SEE: lipoma. the lower mandible and anteriorly to a lipocele (lı˘pЈo¯-se¯l) [Љϩkele, tumor, plastic mold. The plastic sits just behind swelling] The presence of fatty tissue in the lips and in front of the lower inci- a hernia sac. SYN: adipocele; liparocele. sors. It forces the molars back when the lipochondrodystrophy (lı˘pЉo¯-ko˘nЉdro¯- jaw moves. dı˘sЈtro¯-fe¯) [Љϩchondros, cartilage, ϩ lipectomy (lı˘-pe˘kЈto¯-me¯) [Љϩektome, dys, bad, ϩ trephein, to nourish] Mu- excision] Excision of fatty tissues. copolysaccharidosis IH. suction l. SEE: liposuction. lipochondroma (lı˘pЉo¯-ko˘n-dro¯Јma˘) [Љϩ lipedema (lı˘pЉe˘-de¯Јma˘) [Љϩoidema, Љϩoma, tumor] A tumor that is both swelling] Swelling of the skin, esp. of fatty and cartilaginous. the lower extremity, owing to accumu- lipochrome (lı˘pЈo¯-kro¯m) [Љϩchroma, lation of fat and fluid subcutaneously. color] Any one of a group of fat-soluble lipemia (lı˘-pe¯Јme¯-a˘) [Љϩhaima, blood] pigments (e.g., carotene, the fat-soluble An abnormal amount of fat in the blood. yellow pigment found in carrots, sweet alimentary l. An accumulation of fat potatoes, egg yolk, butter, body fat, and in the blood after eating. corpus luteum). l. retinalis A condition in which reti- lipocyte (lı˘pЈo¯-sı¯t) SEE: cell, fat. nal vessels appear reddish white or lipodermatosclerosis Thickening and white; found in cases of hyperlipidemia. red discoloration of the skin as a result SEE: hyperlipoproteinemia. of diminished blood flow, usually caused lipid- SEE: lipo-. by local or regional venous obstruction. lipid(e) (lı˘pЈ˘d,ı −ı¯d) [Gr. lipos, fat] Any lipodystrophy (lı˘pЉo¯-dı˘sЈtro¯-fe¯) [Љϩ one of a group of fats or fatlike sub- dys, bad, ϩ trophe, nourishment] Dis- stances, characterized by their insolu- turbance of fat metabolism. Common bility in water and solubility in fat sol- findings include the localized accumu- vents such as alcohol, ether, and lation of fat under the skin and on the chloroform. The term is descriptive trunk, or fatty atrophy. rather than a chemical name such as gynoid l. Cellulite. protein or carbohydrate. It includes true insulin l. A complication of insulin fats (esters of fatty acids and glycerol); administration characterized by lipoids (phospholipids, cerebrosides, changes in the subcutaneous fat at the waxes); and sterols (cholesterol, ergos- site of injection. The changes may take terol). SEE: fat; cholesterol for table. the form of atrophy or hypertrophy; lipidemia (lı˘pЉı˘-de¯Јme¯-a˘) Lipemia. SEE: rarely are both types present in the atherosclerosis; cholesterol. same patient. Atrophy develops in as lipid histiocytosis Niemann-Pick dis- many as one third of children and ease. women who use insulin regularly, but lipido- [Gr. lipos, fat] SEE: lipo-. rarely in men. The defect in subcuta- lipidosis (lı˘pЉı˘-do¯Јsı˘s) Any disorder of fat neous fat leaves a saucer-like depres- metabolism. sion. Hypertrophy at the injection site arterial l. Arteriosclerosis. occurs in the form of a spongy localized cerebroside l. Gaucher’s disease. area. This complication of insulin ad- lipid storage disease A group of rare in- ministration is slightly more common in herited disorders of fat metabolism in males than in females. It is usually as- which lipids are metabolized abnor- sociated with a history of repetitive use mally and accumulate in tissues such as of one injection site. the brain and peripheral nerves. intestinal l. A disease characterized lipiduria (lı˘pЉı˘-du¯ Јre¯-a˘) [ЉϩGr. ouron, principally by fat deposits in intestinal urine] Lipids in the urine. and mesenteric lymphatic tissue, fatty Lipitor (lı˘pЈı˘-to˘r) SEE: atorvastatin. diarrhea, loss of weight and strength, lipo-, lip-, lipid-, lipido- [Gr. lipos, fat] and arthritis. Combining forms meaning fat. SEE: progressive l. A pathological condi- adipo-; steato-. tion in which there is progressive, sym- lipoarthritis (lı˘pЉo¯-a˘rth-rı¯Јtı˘s) [Љϩar- metrical loss of subcutaneous fat from thron, joint, ϩ itis, inflammation] Ar- the upper part of the trunk, face, neck, thritis associated with the presence of and arms. lipid particles in the joint fluid. lipodystrophy syndrome A side effect lipoaspiration Liposuction. encountered in the treatment of HIV pa- lipoatrophia, lipoatrophy (lı¯Љpo¯-a˘-tro¯Јfe¯- tients with protease inhibitors in which a˘, lı¯Љpo¯-a˘tЈro¯-fe¯) [Љϩa-, not, ϩ tro- they develop abnormal accumulations phe, nourishment] Atrophy of subcu- of body fat (e.g., over the upper back), taneous fatty tissue. This may occur, for hypercholesterolemia, hyperglycemia, example, at the site of insulin injection. hypertriglyceridemia, and insulin resis- short SEE: lipodystrophy. tance. standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh lipofibroma 1349 lipoprotein base of rh lipofibroma (lı˘pЉo¯-fı¯-bro¯Јma˘) [ЉϩL. fi- or trunk but are not metastatic. SEE: bra, fiber, ϩ Gr. oma, tumor] A li- chondrolipoma. poma having much fibrous tissue. SYN: l. arborescens An abnormal treelike fibrolipoma. accumulation of fatty tissue in a joint. lipofilling, lipostructure (lı˘Јpo¯-fı˘lЉı˘ng) cystic l. A lipoma containing cysts. The injection of fat cells or fatty tissue diffuse l. A lipoma not definitely cir- to fill body contours, reduce skin wrin- cumscribed. kles, or eliminate other perceived de- l. diffusum renis A condition in fects in appearance. which fat displaces parenchyma of the lipofuscin (lı˘pЉo¯-fu˘sЈsı˘n) [ЉϩL. fuscus, kidney. SYN: lipomatosis renis. brown] An insoluble fatty pigment l. durum A lipoma with marked hy- found in aging cells. It is the residue of pertrophy of the fibrous stroma and cap- cellular or extracellular material that sule. the cells have ingested but not com- nasal l. A fibrous growth of the sub- pletely digested. SEE: atrophy, brown; cutaneous tissue of the nostrils. free radical. osseous l. A lipoma in which the con- lipofuscinosis (lı˘pЉo¯-fu¯ Љsı˘n-o¯Јsı˘s) [ЉϩЉ nective tissue has undergone calcareous ϩ Gr. osis, condition] Abnormal dep- degeneration. osition of lipofuscin in tissues. l. telangiectodes A rare form of li- neuronal ceroid l. Batten disease. poma containing a large number of lipogenesis (lı˘pЉo˘-je˘nЈe˘-sı˘s) [Gr. lipos, blood vessels. fat, ϩ genesis, generation, birth] Fat lipomatoid (lı˘-po¯Јma˘-toyd) [ЉϩЉϩ formation. eidos, form, shape] Similar to a lipoma. lipogenetic, lipogenic (lı˘pЉo¯-je˘-ne˘tЈ˘k,ı lipomatosis (lı˘pЉo¯-ma˘-to¯Јsı˘s) [Љϩoma, lı˘pЉo¯-je˘nЈı˘k) Producing or produced by tumor ϩ osis, condition] A condition fat. SYN: lipogenous. marked by the excessive deposit of fat lipogenous (lı˘p-o˘jЈe˘-nu˘s) Lipogenetic. in a localized area. lipogranuloma (lı˘pЉo¯-gra˘n-u¯-lo¯Јma˘) [Љϩ l. renis Lipoma diffusum renis. L. granulum, granule, ϩ Gr. oma, tu- lipomatous (lı˘p-o¯Јma˘-tu˘s) 1. Of the na- mor] Inflammation of fatty tissue with ture of lipoma. 2. Affected with lipoma. granulation and development of oily cysts. lipomeningocele (lı˘pЉo¯-me˘-nı˘ngЈgo¯-se¯l) lipogranulomatosis (lı˘pЉo¯-gra˘nЉu¯-lo¯-ma˘- [Љϩmeninx, membrane, ϩ kele, tu- to¯Јsı˘s) [ЉϩЉϩЉϩosis, condition] mor, swelling] A meningocele associ- A disorder of fat metabolism in which a ated with lobules of fat tissue. nodule of fat undergoes central necrosis lipomeria (lı¯Љpo¯-me¯Јre¯-a˘) [Gr. leipein, to and the surrounding tissue becomes leave, ϩ meros, a part] In a deformed granulomatous. fetus, the congenital absence of a limb. lipohyalinosis (lı¯-po¯-hı¯Јa˘-lı˘n-o¯Љsı˘s) De- lipometabolism (lı˘p-o¯-me˘-ta˘bЈo˘l-ı˘zm) [Љ generative changes in small blood ves- ϩЉϩ−ismos, condition] Fat metab- sels, marked by the accumulation of a olism. glassy- or waxy-appearing lipid within lipomyoma (lı˘pЉo¯-mı¯-o¯Јma˘) [Љϩmys, the vessel wall. This type of vascular de- muscle, ϩ oma, tumor] A myoma con- generation occurs in hypertension and taining fatty tissue. atherosclerosis, and predisposes pa- lipomyxoma (lı˘pЉo¯-mı˘ks-o¯Јma˘) [Љϩ tients to small infarcts, esp. in pene- myxa, mucus, ϩ oma, tumor] A mixed trating arteries of the brain. lipoma and myxoma. SYN: myxolipoma. lipoid (lı˘pЈoyd) [Љϩeidos, form, shape] lipopenia (lı˘pЉo¯-pe¯Јne¯-a˘) [Љϩpenia, 1. Similar to fat. 2. Lipid(e). poverty] A deficiency of lipids. lipo- lipoidosis (lı˘p-oy-do¯Јsı˘s) [ЉϩЉϩosis, penic (−nı˘k), adj. condition] Excessive lipid accumula- lipopeptid, lipopeptide (lı˘pЉo¯-pe˘pЈtı˘d, tion. SEE: xanthomatosis; lipidosis. −tı¯d) A complex of lipids and amino ac- arterial l. Arteriosclerosis. ids. cerebroside l. A familial disease lipophagia, granulomatous (lı˘pЉo¯-fa¯Јje¯-a˘) characterized by deposition of glucocer- Intestinal lipodystrophy. ebroside in cells of the reticuloendothe- lipophagy (lı˘-po˘fЈa˘-je¯) The ingestion of lial system. SYN: Gaucher’s disease. fat cells by phagocytes. lipoiduria (lı˘pЉoy-du¯ Јre¯-a˘) [ЉϩЉϩ lipophanerosis (lı˘pЉo¯-fa˘nЉe˘-ro¯Јsı˘s) [Љϩ ouron, urine] Lipoids in the urine. phaneros, visible, ϩ osis, condition] lipolipoidosis (lı˘pЉo¯-lı˘pЉoy-do¯Јsı˘s) [Љϩ The alteration of fat in a cell so that it lipos, fat, ϩ eidos, form, shape, ϩ becomes visible as droplets. osis, condition] Infiltration of fats and lipophil (lı˘pЈo¯-fı˘l) [Љϩphilein, to love] lipoids into a tissue. 1. Having an affinity for fat. 2. Absorb- lipolysis (lı˘p-o˘lЈı˘-sı˘s) [Љϩlysis, disso- ing fat. lution] The decomposition of fat. lipophilia (lı˘pЉo¯-fı˘lЈe¯-a˘) [Љϩphilos, lipolytic (lı˘p-o¯-lı˘tЈı˘k) Relating to lipoly- love] Affinity for fat. sis. lipopolysaccharide (lı˘pЉo¯-po˘lЉe¯-sa˘kЈa˘-rı¯d) lipoma (lı˘-po¯Јma˘ ) [Gr. lipos, fat, ϩ The linkage of molecules of lipids with oma, tumor] A benign fatty tumor. polysaccharides. short They often appear in crops on the arms lipoprotein (lı˘pЉo¯-pro¯Јte¯n) Conjugated standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh lipoprotein 1350 liposome base of rh

chemicals in the bloodstream consisting than high-density, but more than low- of simple proteins bound to fat. Choles- density, lipoproteins. terol, phospholipids, and triglycerides l. lipase ABBR: Lp(a). An enzyme are all fatty components of lipoproteins. produced by many cells. On the surface Analyzing the concentrations and pro- of cells lining the vasculature, it hydro- portions of lipoproteins in the blood can lyzes fat (chylomicrons) and very low- provide important information about density lipoprotein (VLDL) to monogly- patients’ risks of atherosclerosis, coro- cerides to free fatty acids and nary artery disease, and death. intermediate-density lipoprotein (IDL). Lipoproteins are classified as very This enzyme, similar to plasminogen, is low-density (VLDL), low-density (LDL), an important regulator of lipid and lipo- intermediate-density (IDL), and high- protein metabolism. Even though the density (HDL). Increased levels of LDL physiological functions of Lp(a) and apo- and total cholesterol directly raise one’s protein(a) are not fully understood, chances of having coronary heart dis- there is a positive association of plasma ease (CHD). For this reason LDL has Lp(a) with premature myocardial in- been referred to colloquially as “bad” farction. Deficiency of this enzyme leads cholesterol. By contrast, increased lev- to an increase in chylomicrons and els of HDL (“good” cholesterol) are VLDLs, and to low levels of high-density linked with a lowered risk of CHD. The lipoproteins (HDL). Diseases associated National Cholesterol Education Pro- with acquired causes of decreased lipo- gram has designated 70–100 mg/dl or protein lipase include acute ethanol in- less as a desirable level of LDL in those gestion, diabetes mellitus, hypothyroid- already affected by CHD; for people ism, chronic renal failure, and nephrotic without CHD, a desirable level of LDL syndrome. is 100 mg/dl or less. SEE: atherosclero- low-density l. ABBR: LDL. Plasma sis; coronary artery disease; hyperlipo- lipids that carry the majority of the cho- proteinemia; statins; cholesterol for ta- lesterol in plasma. Bound to albumin, ble. LDLs are a proven cause of atheroscle- ETIOLOGY: Elevated levels of lipo- rosis; lowering LDLs with a low-fat diet proteins usually are the result of a diet or with drugs helps to prevent and treat that is excessively rich in fats, saturated coronary artery disease. fats, and cholesterols. In a small num- Lp(a) l. A low-density lipoprotein in ber of patients with extremely high lipo- which apolipoprotein B-100 is linked to protein levels, genetic diseases play a apoprotein(a). It contributes to the ob- part. struction of blood vessels in atheroscle- SYMPTOMS: High lipoprotein levels rosis. may cause no symptoms of their own oxidized low-density cholesterol l. until patients develop arterial block- A form of low-density lipoprotein choles- ages. If arteries become blocked by lipo- terol whose presence in the blood is of- proteins, ischemic symptoms may de- ten associated with unstable coronary velop. events, such as acute myocardial infarc- TREATMENT: Abnormal lipoprotein tion. levels normalize in many patients who very low-density l. ABBR: VLDL. consume less dietary fat and increase Plasma lipids bound to albumin and their level of exercise. When lipopro- consisting of chylomicrons and prelipo- teins do not reach expected levels de- proteins. This class of plasma lipopro- spite diet and exercise, medications to teins contains a greater ratio of lipid improve lipoprotein profiles are pre- than the low-density lipoproteins and is scribed. These include drugs such as ni- the least dense. acin, bile-acid binding resins, and the liposarcoma (lı˘pЉo¯-sa˘r-ko¯Јma˘) [Gr. lipos, statins. fat, ϩ sarx, flesh, ϩ oma, tumor] A l. (a) A lipid-protein complex that is malignant tumor derived from embry- found normally in the plasma in small onal fat cells. amounts in all people, but in very high liposculpture (lı˘pЉo¯-sku˘lpЈche˘r) The sur- concentrations in some persons with fa- gical removal of fat from one part of the milial forms of atherosclerosis. body to another in order to smooth wrin- alpha l. High-density lipoprotein. kles, fill hollows, or create new body con- high-density l. ABBR: HDL. Plasma tours. lipids bound to albumin, consisting of liposhaver (liЈpo¯-sha¯-ver) A device used lipoproteins. They contain more protein in plastic surgery to carve out unwanted than either very low-density lipopro- fat and create smooth contours beneath teins or low-density lipoproteins. High- the skin. density lipoprotein cholesterol is the so- liposis (lı˘-po¯Јsı˘s) [Љϩosis, condition] called good cholesterol; a high level is Adiposis. desirable. SYN: alpha l. liposoluble (lı˘pЉo¯-so˘lЈu¯-b’l) [ЉϩL. so- intermediate-density l. ABBR: IDL. lubilis, soluble] Soluble in fats. Plasma lipids bound to albumin, con- liposome (lı˘pЈo¯-so¯m) [Љϩsoma, body] short sisting of lipoproteins with less protein The sealed concentric shells formed standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh lipostomy 1351 Lisch nodule base of rh

when certain lipid substances are in an lipping (lı˘pЈı˘ng) A growth of bony tissue aqueous solution. As it forms, the lipo- beyond the joint margin in degenerative some entraps a portion of the solution joint disease. in the shell. Liposomes may be manu- lip-pit syndrome Van der Woude’s syn- factured and filled with a variety of drome. medications. These have been used to lip reading Interpreting what is being deliver substances to particular organs. said by watching the speaker’s lip and These drug forms may be more effective facial movements and expression. This and less toxic than drugs given by other method is used as a means of speech dis- means. crimination by people with hearing im- lipostomy (lı¯-po˘sЈto¯-me¯) [Gr. leipein, to pairments. fail, ϩ stoma, mouth] Congenital ab- lipuria (lı˘-pu¯ Јre¯-a˘) [Gr. lipos, fat, ϩ sence or extreme smallness of the ouron, urine] Fat in the urine. mouth. liquefacient (lı˘kЉwe˘-fa¯Јshe˘nt) [L. liquere, liposuction (lı¯Јpo¯-su˘kЉshu˘n) The re- to flow, ϩ facere, to make] 1. An agent moval of subcutaneous fat tissue with a that converts a solid into a liquid. blunt-tipped cannula introduced into 2. Converting a solid into a liquid. the fatty area through a small incision. liquefaction (lı˘kЉwe˘-fa˘kЈshu˘n) 1. The Suction is then applied and fat tissue re- conversion of a solid into a liquid. 2. The moved. Liposuction is a form of plastic conversion of solid tissues to a fluid or surgery intended to remove adipose tis- semifluid state. sue from localized areas of fat accumu- liquescent (lı˘k-we˘sЈse˘nt) [L. liquescere, lation as on the hips, knees, buttocks, to become liquid] Becoming liquid. thighs, face, arms, or neck. To be cos- liquid (lı˘kЈwı˘d) [L. liquere, to flow] metically successful, the skin should be 1. Flowing easily. 2. The state of matter elastic enough to contract after the un- in which a substance flows without be- derlying fat has been removed. Liposuc- ing melted. SEE: emulsion; liquefacient; tion will not benefit dimpled or sagging liquefaction. skin or flabby muscles. There are no l. measure A measure of liquid ca- health benefits to liposuction, and as pacity. with any surgery there may be risks liquid air therapy The therapeutic appli- such as infection, severe postoperative cation of air that is so cold as to be liq- pain, cardiac arrhythmias, shock, and uefied. SEE: CO2 therapy; cryotherapy; even death. There is also the possibility hypothermia. the results will be unsatisfactory to the liquid-based cytology ABBR: LBC. A patient. SYN: lipoaspiration; suction li- means of performing a Papanicolaou pectomy. Ј Љϩ test in which the head of the plastic lipotropic (lı˘p-o¯-tro˘p ı˘k) [ trope, a spatula used to obtain cells from the en- turning] Having an affinity for lipids, docervix is inserted directly into a vial as with certain dyes (e.g., Sudan III, containing a fluid cellular preservative. which stains fat readily). The vial is spun in the laboratory, and l. factors Compounds that promote a pellet of pure cells is obtained. This the transportation and use of fats and cellular layer is then deposited on a mi- help to prevent accumulation of fat in the liver. croscope slide and examined for evi- lipotropism, lipotropy (lı˘-po˘tЈro¯-pı˘zm, dence of cellular atypia or frank cancer. −pe¯) [Љϩtrope, a turn, ϩ −ismos, con- The liquid-based cytology differs from dition] 1. Having the action of remov- traditional cervical cytology in that the ing fat deposits in the liver. 2. An agent contents of the spatula are not smeared that acts to remove fat from the liver. directly onto a microscope slide. This re- lipovaccine (lı˘pЉo¯-va˘kЈse¯n) A vaccine duces the number of specimens received suspended in vegetable oil. by the laboratory that are unable to be lipoxidase (lı˘-po˘kЈsı˘-da¯s) An enzyme interpreted pathologically. that catalyzes the oxidation of the dou- liquid crystal display ABBR: LCD. A ble bonds of an unsaturated fatty acid. type of electronic display unit used on SYN: lipoxygenase. devices from watches to clinical labora- lipoxin (lı˘-po˘kЈsı˘n) Any of a group of tory instruments. It is very efficient and eicosanoids formed by the action of consumes little energy or power. phospholipases on cell membrane phos- liquor (lı˘kЈe˘r) [L.] 1. Any liquid or fluid. pholipids. Some lipoxins have anti-in- 2. An alcoholic beverage. 3. A solution of flammatory effects, but some promote medicinal substance in water. inflammation and hypersensitivity re- l. amnii The amniotic fluid, a clear actions. SEE: leukotriene; prostaglan- watery fluid that surrounds the fetus in din. the amniotic sac. SEE: hydramnion. lipoxygenase (lı˘-po˘ksЈı˘-je˘-na¯s) Lipoxi- l. folliculi The fluid contained in the dase. graafian follicle. Lippes loop (lı˘Јpe¯z) [Jacob Lippes, U.S. l. sanguinis Blood serum or plasma. obstetrician, b. 1924] A type of intra- Lisch nodule (lı˘sh) [Karl Lisch, Ger. sci- short uterine contraceptive device. entist, 1907–1999] A melanocytic ha- standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh Lisfranc’s dislocation 1352 Listing’s plane base of rh

martoma projecting from the surface of ism is destroyed by heat; therefore the the iris of the eye. It is a well-defined, risk of contracting listeriosis derives dome-shaped elevation that is clear to from consuming foods served cold or not yellow or brown. These growths, which heated to 158ЊF for at least 2 min. The do not cause ophthalmological compli- Department of Agriculture recommends cations, may be seen without magnifi- that people at risk for infection should cation, but examination with use of a not eat hot dogs, lunch meats, dried sau- slit lamp is needed to differentiate them sage, raw milk, and soft cheese (e.g., from nevi of the iris. Lisch nodules are brie, blue cheese) or cheese made from found only in patients with neurofibro- raw milk. In pregnant women, Listeria matosis, type 1. infects the amniotic fluid and causes Lisfranc’s dislocation (lı˘s-fra˘nksЈ) spontaneous abortion, stillbirth, or pre- [Jacques Lisfranc, Fr. surgeon, 1790– mature birth with lethal listeriosis; in 1847] A dislocation of the tarsometa- immunosuppressed adults and neo- tarsal joints of the foot by direct or in- nates, it most commonly causes menin- direct mechanisms. Accompanying frac- gitis. ture is common. Person-to-person transmission is pri- Lisfranc’s ligament The ligament joining marily in utero or during passage the first cuneiform bone of the ankle to through an infected birth canal. Other the second metatarsal. modes of transmission include inhala- lisinopril (lı¯-sı˘nЈo¯-prı˘l) An angiotensin- tion of contaminated dust; contact with converting enzyme inhibitor used, e.g., infected animals, contaminated sewage, to treat high blood pressure and conges- mud, or soil, or with feces containing the tive heart failure. bacteria. Most often contact with L. lisp (lı˘sp) [AS. wlisp, lisping] A substi- monocytogenes results in a transient tution of sounds owing to a defect in asymptomatic carrier state, but some- speech, as of the “th” sounds of “thin” times bacteremia and a generalized feb- and “then” for “s” and “z.” rile illness is produced. Transplacental lissencephalous (lı˘sЉse˘n-se˘fЈa˘-lu˘s) [Gr. infections may cause abortion, prema- lissos, smooth, ϩ enkephalos, brain] ture delivery, stillbirth, or early neona- Pert. to a condition in which the brain tal death, though the pregnant woman is smooth owing to failure of cerebral herself may experience only mild ill- gyri to develop. ness. lissotrichy (lı˘s-so˘tЈrı˘-ke¯) [Љϩthrix, TREATMENT: Ampicillin or penicillin hair] The condition of having straight G IV for 3 to 6 weeks is the treatment hair. of choice, esp. since these drugs easily Lister, Lord Baron Joseph (lı˘sЈte˘r) Brit- cross the blood-brain barrier to treat ish surgeon, 1827–1912, who developed meningitis. Ampicillin plus ceftriaxone the technique of antiseptic surgery, sub- or cefotaxime or ampicillin plus an ami- sequently evolving into aseptic surgery, noglycoside also have proven effective without which modern surgery would against Listeria meningitis. Pregnant not be possible. patients must be treated promptly and Listeria (lı˘-ste˘rЈe¯-a˘) A genus of gram- vigorously to manage fetal infection. If positive, non–spore-forming coccoba- the patient is allergic to penicillin, then cilli that may be found singly or in fila- trimethoprim or sulfamethoxazole ments. They are normal soil should be used. Dexamethasone may be inhabitants. given before antibiotic therapy to de- Listeria monocytogenes The causative crease cerebral edema. agent of listeriosis. This species lives in PATIENT CARE: Public education is soil or the intestines of animals and may needed to inform pregnant women, contaminate food, esp. milk or meat. Its older adults, people on immunosuppres- growth is not inhibited by refrigeration. sive drug therapy, or those with HIV in- listeriosis, listerosis (lı˘s-te˘rЉe¯-o¯Јsı˘s, fection of the danger of ready-to-eat lı˘sЉte˘r-o¯Јsı˘s) Infection with Listeria mo- foods such as cold cuts and soft cheeses. nocytogenes, which causes mild food poi- Safe food handling techniques to mini- soning in the healthy and severe sys- mize the risk of infection include wash- temic disease in immunosuppressed ing hands well (at least 20 sec) when patients, older adults, pregnant women, handling ready-to-eat cold foods, wash- fetuses, and neonates (during the first 3 ing cutting boards and other utensils weeks of life). The organism may be with hot soapy water before using them found in unpasteurized milk, unpro- for another food, keeping uncooked cessed soft cheeses, processed foods foods separated from cooked foods, and (e.g., lunch meats) contaminated after washing all fruits and vegetables before production, or vegetables contaminated eating, even those that come from a pri- by soil or water containing the organ- vate garden. ism. Unlike other food-borne pathogens, Listing’s plane [Johann Benedict Listing, Listeria grows in refrigerated food; it Ger. physiologist, 1808–1882] A trans- also grows on the walls of refrigerators verse vertical plane lying perpendicular short and can infect other foods. The organ- to the anteroposterior axis of the eye standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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and containing the center of motion of level of the drug in patients taking this the eyes. It also contains the transverse therapy; samples should be taken 8 to 10 and vertical axes of voluntary ocular ro- hr after the last dose and at intervals after tation. medication. liter (le¯Јte˘r) [Fr. litre, liter] SI (metric) fluid measure; equivalent to 1000 ml, litho-, lith- [Gr. lithos, stone] Combining 270 fl drams, 61 cu in, 33.8 fl oz, or forms meaning stone or calculus. 1.0567 qt. The volume occupied by 1 kg lithocenosis (lı˘thЉo¯-se˘n-o¯Јsı˘s) [Љϩke- of water at 4ЊC and 760 mm Hg pres- nosis, evacuation] The removal of sure. SEE: metric system. crushed fragments of kidney stones NOTE: It is common to define a liter from the bladder. as 1000 cc. This is not quite correct be- lithoclast (lı˘thЈo¯-kla˘st) [Љϩklastos, cause 1 ml equals 1.000028 cc. Thus, liq- broken] Forceps for breaking up large uid volume should be expressed in mil- stones. liliters rather than in cubic centimeters. lithoclasty (lı˘thЈo¯-kla˘sЉte¯) The crushing literate Being able to read and write, and of a stone into fragments that may pass to use written language as in under- through natural channels. standing graphs, charts, tables, maps, lithocystotomy (lı˘thЉo¯-sı˘s-to˘tЈo¯-me¯) [Љ symbols, and formulas. ϩ kystis, bladder, ϩ tome, incision] lith- SEE: litho-. Incision of the bladder to remove a kid- lithectasy (lı˘th-e˘kЈta˘-se¯) [Gr. lithos, ney stone. stone, ϩ ektasis, dilatation] The re- lithogenesis (lı˘thЉo¯-je˘nЈe˘-sı˘s) [Љϩgen- moval of a kidney stone from the blad- nan, to produce] Formation of calculi. der through the dilated urethra. lithokelyphopedion (lı˘thЉo¯-ke˘lЉı˘-fo¯-pe¯Јde¯- lithectomy (lı˘-the˘kЈto¯-me¯) [Љϩektome, o˘n) [Љϩkelyphos, sheath, ϩ pai- excision] The surgical removal of a cal- dion, child] Calcification of both the fe- culus. tus and the membranes of a lithopedion. lithemia (lı˘th-e¯Јme¯-a˘) [Љϩhaima, lithokelyphos (lı˘thЉo¯-ke˘lЈı˘-fo˘s) [Љϩke- blood] An outdated term for hyperuri- lyphos, sheath] A type of lithopedion in cemia. which only the membranes are calcified. lithiasis (lı˘th-ı¯Јa˘-sı˘s) Stone formation. litholabe (lı˘thЈo¯-la¯b) [Љϩlambanein, to lithium (lı˘thЈe¯-u˘ m) [Gr. lithos, stone] hold] A device for holding a stone dur- SYMB: Li. A metallic element; atomic ing its removal. weight 6.941; atomic number 3. litholapaxy (lı˘th-o˘lЈa˘-pa˘ksЉe¯) [Gr. lithos, l. carbonate A drug used to treat bi- stone, ϩ lapaxis, evacuation] The op- polar disorder. Given orally, it is readily eration of crushing a stone in the blad- absorbed and eliminated at a fast rate der followed by immediate washing out for 5 to 6 hr and much more slowly over of the crushed fragments through a the next 24 hr. SEE: bipolar disorder. catheter. SEE: percutaneous ultrasonic The dose is adjusted as needed to pro- lithotriptor. duce a plasma level of 0.8 mEq/L. When lithology (lı˘th-o˘lЈo¯-je¯) [Љϩlogos, word, the dose has been found to produce the reason] The science dealing with cal- optimal plasma concentration, blood culi. analysis is done every 3 months unless litholysis (lı˘th-o˘lЈı˘-sı˘s) [Љϩlysis, dis- symptoms suggestive of toxicity are solution] Dissolving of stones. present. Plasma levels of 2 mEq/L or lithometer (lı˘th-o˘mЈe˘-te˘r) [Љϩmetron, more cause serious toxic effects (e.g., measure] An instrument for estimating stupor or coma, muscular rigidity, the size of calculi. marked tremor, and, in some cases, ep- lithometra (lı˘th-o¯-me¯Јtra˘) [Љϩmetra, ileptic seizure). uterus] Uterine tissue ossification. Side effects, including fatigue, weak- lithonephrotomy (lı˘thЉo¯-ne¯-fro˘tЈo¯-me¯) [Љ ness, fine tremor of the hands, nausea ϩ nephros, kidney, ϩ tome, incision] and vomiting, thirst, dry mouth, and An incision of the kidney for removal of polyuria, may be noticed in the first a kidney stone. week of therapy. Most will disappear, lithopedion (lı˘thЉo¯-pe¯Јde¯-o˘n) [Љϩpai- but the thirst, polyuria, and tremor tend dion, child] A uterine or extrauterine to persist. Dry mouth may be severe fetus that has died and become calcified. enough to promote dental decay. SYN: ostembryon; osteopedion. lithotome (lı˘thЈo¯-to¯m) [Љϩtome, inci- Decreased dietary sodium intake sion] An instrument for performing li- lowers the excretion rate of lithium. thotomy. It should not be administered to patients lithotomy (lı˘th-o˘tЈa˘-me¯) [Љϩtome, in- following a salt-free diet. The risk of tox- cision] The incision of a duct or organ, icity is very high in patients with signifi- esp. of the bladder, for removal of a cant renal or cardiovascular disease, se- stone. SEE: lithotomy position. vere debilitation, dehydration, sodium PATIENT CARE: Noninvasive mea- depletion, or in patients receiving diuret- sures and prescribed analgesic agents ics or nonsteroidal anti-inflammatory are provided to relieve pain. Fluid bal- short drugs. It is essential to monitor the blood ance is monitored, and, unless other- standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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wise contraindicated by cardiac or renal status, fluid intake of 4 L/day is recom- mended to maintain a urine output of 3 to 4 L/day, which aids in the passage of small calculi (up to 5 mm in diameter) and prevents ascending infections. Sup- plemental IV fluids are provided if the patient is unable to tolerate the re- A quired volume by mouth. Vital signs and laboratory studies are monitored for signs of infection, and prescribed an- tibiotics are administered. The health care professional prepares the patient for lithotripsy or surgery, as indicated, by explaining postoperative equipment, care procedures, and expected sensa- tions. Any incisions are assessed for drainage and healing; the character and amount of drainage are documented, usually via a ureteral catheter or ne- B phrotomy tube (which should never be EXTRACORPOREAL SHOCK WAVE irrigated unless specifically prescribed). LITHOTRIPSY Using aseptic techniques, the health care professional protects surrounding Shock waves are transmitted through skin from excoriation by redressing fre- water to break up gallstones. A. Position quently. All urine is strained for evi- for stones in gallbladder. Patient is lying dence of stones, and any solid material on a fluid-filled bag; B. Position for is sent for analysis. Splinting the inci- stones in common bile duct. Patient is in sion with a small pillow assists the pa- a water bath. tient to mobilize and to carry-out pul- monary hygiene. Based on laboratory lithotripsy. 2. An agent that dissolves analysis of the stone, treatments are stones. prescribed to prevent recurrence. lithotriptor (lı˘thЈo¯-trı˘pЉtor) [Љϩtripsis, bilateral l. A lithotomy performed friction] A device for breaking up kid- with the incision across the perineum. ney stones. high l. A lithotomy performed electrohydraulic l. An intracorporeal through a suprapubic incision. lithotriptor (i.e., one that is inserted lateral l. A lithotomy performed with into a body cavity). This fluid-filled de- the incision from the front of the rectum vice uses electrically generated shock to one side of the raphe. waves next to stones in order to frag- median l. A lithotomy performed ment them. with the incision in the median line in laser l. A lithotriptor that fragments front of the anus. stones by applying photothermal en- rectal l. A lithotomy performed ergy. An endoscope is inserted through through the rectum. the urethra into the bladder, ureter, or vaginal l. A lithotomy performed renal pelvis and is placed alongside the with the incision through the vaginal stone. Application of a laser causes the wall. stone to break apart. lithotony (lı˘th-o˘tЈo¯-ne¯) [Gr. lithos, stone, percutaneous ultrasonic l. A device ϩ teinein, to stretch] The removal of a that uses ultrasound to break up kidney kidney stone through a small bladder stones and gallstones. The sound waves incision that is instrumentally dilated. are applied to the outside of the body lithotresis (lı˘thЉo¯-tre¯Јsı˘s) [Љϩtresis, and penetrate to the calculi. SEE: extra- boring] The drilling or boring of holes corporeal shock wave lithotripsy. in a calculus to facilitate crushing. More lithotriptoscopy (lı˘thЉo¯-trı˘p-to˘sЈko¯-pe¯) [Љ recently, an ultrasonic probe is em- ϩЉϩskopein, to examine] The ployed. crushing of a kidney stone under direct lithotripsy (lı˘thЈo¯-trı˘pЉse¯) [Љϩtribein, vision using a lithotriptoscope. to rub] 1. The use of sound waves to lithotrity (lı˘th-o˘tЈrı˘-te¯) The crushing of a fragment or crush stones obstructing kidney stone to small fragments in the the bladder, gallbladder, ureter, or uri- bladder. nary bladder. 2. The production of shock lithoxiduria (lı˘thЉo˘ks-ı˘-du¯ Јre¯-a˘) [ЉϩL. waves by use of an external energy oxidum, oxide, ϩ Gr. ouron, urine] source in order to crush renal stones. The presence of xanthic oxide in the extracorporeal shock-wave l. urine. ABBR: ESWL. The fragmentation of litigation (lı˘tЉı˘-ga¯Јshu˘n) [L. litigatio, dis- kidney stones with an extracorporeal pute, lawsuit] A lawsuit or legal action shock-wave lithotriptor. SEE: illus. that determines the legal rights and short lithotriptic (lı˘th-o¯-trı˘pЈtı˘k) 1. Pert. to remedies of the person or party. standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh litmus 1355 liver base of rh litmus (lı˘tЈmu˘s) A blue dyestuff made by papilla of Vater. A ring of smooth mus- treating coarsely powdered lichens, cle at the terminal portion of the chole- such as those of the genus Roccella, with dochus, the sphincter of Oddi, permits ammonia. the passage of bile into the duodenum l. paper Chemically prepared blue by relaxing. The bile leaving the liver paper that is turned red by acids and enters the gallbladder, where it under- remains blue in alkali solutions; pH goes concentration principally through range is 4.5 to 8.5. SEE: indicator. loss of water absorbed by the gallblad- litter (lı˘tЈte˘r) [O.Fr. litiere, offspring at der mucosa. When bile is needed in the birth, bed] 1. A stretcher for carrying small intestine for digestive purposes, the wounded or the sick. 2. The young the gallbladder contracts and the produced at one birth by a multiparous sphincter relaxes, thus permitting es- mammal. cape of the viscid gallbladder bile. Or- littritis (lı˘t-trı¯Јtı˘s) An inflammation of dinarily, the sphincter of Oddi is con- the urethral glands. tracted, shutting off the duodenal Litzmann’s obliquity (lı˘tsЈma˘nz) [Karl entrance and forcing the bile to enter K. T. Litzmann, Ger. gynecologist, the gallbladder after leaving the liver. 1815–1890] Posterior parietal presen- The functional units of the liver are tation of the fetal head during labor. the liver lobules, six-sided aggregations SYN: posterior asynclitism. of hepatocytes permeated by capillaries lived experience (lı˘vd) The subjective called sinusoids. Lining these sinusoids perception of one’s experience of health are Kupffer cells, the macrophages of or illness. Associated with Rosemarie the liver. Parse’s Nursing Theory of Human be- BLOOD SUPPLY: The blood supply coming, it emphasizes the nurse’s need consists of oxygenated blood from the to understand the personal health ex- hepatic artery, a branch of the celiac ar- perience of patients, rather than to col- tery, and blood from all the digestive or- lect data from patients as objects. SEE: gans and spleen by way of the portal Nursing Theory Appendix. vein. The end products of digestion and livedo (lı˘v-e¯Јdo¯) [L. livedo, lividness] A other materials thus pass through the mottled staining of the skin, often blue liver before entering general circula- or purple, as may be seen in a bruise. tion. SEE: lividity. NERVE SUPPLY: The nerve supply l. reticularis Semipermanent bluish consists of parasympathetic fibers from mottling of the skin of the legs and the vagi and sympathetic fibers from hands. It is aggravated by exposure to the celiac plexus via the hepatic nerve. cold. FUNCTION: The liver is one of the liver (lı˘vЈe˘r) [AS. lifer] The largest solid most metabolically active organs of the organ in the body, situated on the right body. Amino acid metabolism: It synthe- side below the diaphragm. The liver oc- sizes nonessential amino acids, deami- cupies the right hypochondrium, the ep- nates excess amino acids for use in en- igastrium, and part of the left hypochon- ergy production, and forms urea, which drium, and is level with the bottom of the kidneys excrete. Bile production: It the sternum. Its undersurface is con- is responsible for the production of bile cave and covers the stomach, duode- salts, which emulsify fats in the small num, hepatic flexure of colon, right kid- intestine; 800 to 1000 ml of bile is se- ney, and adrenal capsule. The liver creted in 24 hr, and the secretion rate is secretes bile and is the site of numerous increased greatly during digestion of metabolic functions. SEE: illus. meals rich in fats. Carbohydrate metab- ANATOMY: The liver has four lobes, olism: It converts monosaccharides five ligaments, and five fissures and is other than glucose to glucose, and stores covered by a tough fibrous membrane, excess glucose as the starch glycogen, Glisson’s capsule, which is thickest at until such energy is needed. Detoxifica- the transverse fissure. At this point the tion: It produces enzymes to metabolize capsule carries the blood vessels and he- potentially harmful substances found in patic duct, which enter the organ at the the portal circulation (e.g., alcohol, am- hilus. Strands of connective tissue orig- monia, indole, many medications, and inating from the capsule enter the liver skatole) into less toxic ones. Endocrine parenchyma and form the supporting functions: It facilitates the conversion of network of the organ and separate the levothyroxine to the more metabolically functional units of the liver, the hepatic active thyroid hormone, triiodothyro- lobules. nine. Excretion: It discharges the break- The many intrahepatic bile ducts con- down products of hemoglobin (bilirubin verge and anastomose, finally forming and biliverdin) into the bile; these are the secretory duct of the liver, the he- eliminated in feces. Fat metabolism: It patic duct, which joins the cystic duct synthesizes cholesterol as well as lipo- from the gallbladder to form the com- proteins for the transport of fat to other mon bile duct or the ductus choledo- body tissues; it converts fatty acids to short chus, which enters the duodenum at the acetyl groups or ketones, so they may be standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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RIGHT HEPATIC VEIN INFERIOR VENA CAVA LEFT HEPATIC VEIN LIVER

CYSTIC DUCT

HEPATIC DUCT

COMMON BILE DUCT

HEPATIC ARTERY

PORTAL VEIN

CENTRAL VEIN A (BRANCH OF HEPATIC VEIN) LIVER LOBULE GALLBLADDER

SINUSOIDS

BILE DUCT

BRANCH OF PORTAL VEIN

BRANCH OF HEPATIC ARTERY

BILE DUCT

HEPATOCYTES

B

(A) LIVER AND GALLBLADDER, (B) LOBULE

used as energy sources. Phagocytosis: organ includes indirect assessments Its macrophages (Kupffer cells) scav- (e.g., for jaundice [skin color], palmar enge bacteria, other pathogens, and se- erythema, and spider telangiectasias nescent red blood cells from the portal and other signs of chronic liver disease. circulation. Protein synthesis: It manu- Auscultation of the liver may reveal factures albumin, alpha-globulins and bruits associated with liver cancer; aus- beta-globulins, complement compo- cultation also is used to make a crude nents, and clotting factors, some of estimate of organ size. Percussion of the which are dependent on vitamin K. liver, which is performed in the right Storage: It stores copper, iron, vitamin midclavicular line, provides another B12, and the fat-soluble vitamins A, D, method for roughly estimating size. Pal- E, and K. pation of the organ may reveal tender- EXAMINATION: The liver is exam- ness, irregular edges, masses, or tu- ined by inspection, auscultation, per- mors. short cussion, and palpation. Inspection of the abscess of l. A localized collection of standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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pus in the liver caused by pathogenic or- in the liver as a result of infection with ganisms such as those of Streptococcus anaerobic bacteria. This produces a species; Staphylococcus; or Entamoeba honeycomb appearance in the liver tis- histolytica. sue. SYMPTOMS: The patient will have hobnail l. Degeneration of the liver high fevers; sweats and chills; and an characterized by fatty changes, fibrous enlarged, painful, tender liver, which scarring, nodular degeneration, and at- may be bulging and fluctuating. Pus rophy of the liver with the surface cov- may be obtained by aspiration. ered with brown or yellow nodules. This PROGNOSIS: Embolic (multiple) ab- condition is seen in chronic alcoholism scesses are generally fatal. Traumatic and malnutrition. abscesses, or those due to an amebic inflammation of l. Hepatitis. dysentery, may terminate favorably af- nutmeg l. Chronic passive conges- ter spontaneous or induced evacuation. tion of the liver, which produces a red- amyloid l. An enlargement of the dened central portal area and a yel- liver caused by the deposition of amy- lowish periportal zone. loid proteins. SYN: lardaceous liver. shock l. A colloquial term for injury SYMPTOMS: The liver is enlarged, to the liver resulting from insufficient smooth, firm, and painless. Infiltration blood flow, e.g., in patients who have of other organs may cause kidney fail- suffered an episode of severe hypoten- ure, intercerebral bleeding, heart fail- sion. A hallmark of this condition is a ure, anemia, and other diseases and sudden and marked elevation in liver conditions. enzyme levels, such as alanine amino- PROGNOSIS: The prognosis is unfa- transferase (ALT). vorable. l. spots A popular term for pigmen- artificial l. A biomechanical device tary skin discolorations, usually in yel- typically combining a system of filters to low-brown patches. SEE: Lentigo seni- remove toxins from the blood with he- lis. patic cells or tissue. It is designed to wandering l. Floating liver. support patients with hepatic failure liver function, risk for impaired At risk temporarily until a donor liver becomes for liver dysfunction. SEE: Nursing Di- available for transplantation. agnoses Appendix. biliary cirrhotic l. Cirrhosis of the liver function test A blood test for a spe- liver caused by fibrous tissue formed, as cific aspect of liver metabolism. Because a result of infection or obstruction of the of the diversity of liver functions and the bile ducts. disorders that may affect those func- cancer of l. Malignancy of the liver tions, no single test provides a reliable that results either from spread from a measure of overall liver function. The primary source or from primary tumor ability to excrete bile pigments is mea- of the liver itself. The former is the more sured by determining the serum biliru- frequent cause. Male sex, hepatitis B or bin level; the levels of serum enzymes C, cirrhosis, and other liver diseases are such as the aminotransferases aspar- predisposing factors. The liver is the tate and alanine may be used to assess most common site of metastatic spread damage to the liver cells and biliary of tumors that disseminate through the tract obstruction or dysfunction. Levels bloodstream. The prognosis for survival of the serum proteins albumin and glob- is from a few months to 1 yr. ulin and their ratio are used to judge the SYMPTOMS: The disease may cause synthetic functions of the liver. Certain severe pain and tenderness; cachexia blood clotting factors are also synthe- (i.e., loss of weight); and encephalopa- sized in the liver, and abnormalities thy. Jaundice is common. The liver is may indicate impairments in hepatic enlarged, its surface is nodular, and a synthesis. Blood ammonia levels are el- central depression or umbilications can evated in some patients with either often be detected. acute or chronic liver disease; marked cirrhosis of l. SEE: cirrhosis. elevations may suggest acute or chronic cysts of l. Simple cysts, usually small liver failure. SEE: liver. and single; hydatid cysts; or cysts asso- liver transplantation The surgical im- ciated with cystic disease of the liver, a plantation of a donor liver into a patient rare condition usually associated with with end-stage liver disease, whether it congenital cystic kidneys. SEE: Echi- is caused by alcoholic cirrhosis, chronic nococcus granulosus; hydatid. cholestatic diseases, chronic or fulmi- fatty l. Degenerative changes in liver nant hepatitis, or toxic liver destruc- cells owing to fat deposits in the cells. tion. Immunosuppressive drugs (such fibrous capsule of the l. Glisson’s as cyclosporine) must be taken after the capsule. SEE: under Glisson, Francis. procedure to prevent rejection of the l. flap Asterixis. grafted organ. With optimal care, about floating l. An easily displaced liver. 75% of grafted livers remain functional SYN: wandering l. after 1 yr. Patients with human im- short foamy l. The presence of gas bubbles munodeficiency virus or uncontrolled standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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systemic infections, metastatic cancer, tration of a drug to quickly achieve a active alcoholism, or other severe car- therapeutic level. diac, pulmonary, or neurological ill- loading, bicarbonate The ingestion of so- nesses are not candidates for the pro- dium bicarbonate in an effort to neu- cedure. In the U.S. about 4000 liver tralize excessive lactic acid produced in transplants are performed annually. the muscles during exercise or to treat livid (lı˘vЈı˘d) [L. lividus, lead-colored] acidosis in chronic renal failure. 1. Ashen, cyanotic. 2. Discolored, black loading, carbohydrate SEE: carbohy- and blue. drate loading. lividity (lı˘-vı˘dЈı˘-te¯) 1. Skin discoloration, loading, glycogen A dietary regimen as from a bruise or venous congestion. used to fill the body’s glycogen storage SYN: livor. 2. The state of being livid. areas (i.e., the liver and muscles). SEE: postmortem l. A dark blue staining carbohydrate loading. of the dependent surface of a cadaver, loading test The administration of a sub- resulting from the pooling and conges- stance to determine the individual’s tion of blood. SEE: livor mortis. ability to metabolize or excrete it. Thus, living will An advance directive, pre- a glucose tolerance test is one form of pared when an individual is alive, com- this test. petent, and able to make decisions, re- loaiasis (lo¯Љa˘-ı¯Јsı˘s) Loiasis. garding that person’s specific Loa loa (lo¯Јa˘) [W. African] The African instructions about end-of-life care. Liv- eyeworm, a species of filarial worm that ing wills allow people to specify whether infests the subcutaneous tissues and they would want to be intubated, ven- conjunctiva of humans. Its migration tilated, treated with pressor drugs, causes itching and a creeping sensation. shocked with electricity (to stop life- Sometimes it causes itchy edematous threatening heart rhythms), and fed or areas known as Calabar swellings. It is hydrated intravenously (if unable to transmitted by flies of the genus Chry- take food or drink). Some also specify sops. SEE: illus. the person or persons who have power of attorney to make health care deci- sions on the patient’s behalf, if the pa- tient is no longer competent to make choices for himself or herself. SEE: ad- vance directive. livor (lı¯Јvor) [L., a black-and-blue spot] Lividity (1). l. mortis SYN: Postmortem lividity. lixiviation (lı˘ksЉı˘v-e¯-a¯Јshu˘n) [L. lixivia, lye] Leaching. LLE left lower extremity. LLETZ large loop excision of the transfor- mation zone. LOA LOA IN BLOOD LLQ left lower quadrant (of abdomen). ϫ LMA left mentoanterior fetal position. (Orig. mag. 400) SEE: presentation for illus. lobar (lo¯Јba˘r) [Gr. lobos, lobe] Pert. to a LMP left mentoposterior fetal position; lobe. last menstrual period. SEE: presenta- lobate (lo¯Јba¯t) [L. lobatus, lobed] tion for illus. 1. Pert. to a lobe. 2. Having a deeply un- LMT left mentotransverse fetal position. dulated border. 3. Producing lobes. SEE: presentation for illus. lobbying Attempting to shape legisla- LOA left occipitoanterior fetal position. tion, influence legislators, or mold pub- SEE: presentation for illus. lic opinion. load 1. A weight supported or force im- lobe (lo¯b) [Gr. lobos, lobe] 1. A fairly posed. 2. A substance given to test body well-defined part of an organ separated function, esp. metabolic function. SEE: by boundaries, esp. glandular organs loading test. and the brain. 2. A major part of a tooth glycemic l. The glycemic index of a formed by a separate calcification cen- food multiplied by the its carbohydrate ter. content (in grams) divided by 100. anterior l. of hypophysis The ante- load-distributing band cardiopulmonary rior portion of the pituitary gland, con- resuscitation ABBR: LDB-CPR. An sisting of the pars distalis and pars tub- automated means of performing chest eralis. compressions during cardiopulmonary caudate l. of liver The irregular resuscitation, in which the thorax of the quadrangular portion of liver behind patient is wrapped in a compression belt the fissure for the portal vein and be- that alternately squeezes the chest and tween the fissures for the vena cava and allows it to return to its original shape. ductus venosus. short loading The rapid or repeated adminis- central l. The island of Reil, which standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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forms the floor of the lateral cerebral quially as “puke weed.” It is a perennial, fossa. flowering plant that is an expectorant cerebellar lobe One of the three ma- and emetic. It has been used in comple- jor divisions of the cerebellum. The an- mentary medicine as a treatment for terior lobe or paleocerebellum is largely asthma. concerned with coordinating posture lobeline (lo˘bЈe˘-le¯n) The chief constituent and with the muscle tone of the trunk of lobelia. and limbs. The posterior lobe or neocer- lobi (lo¯Јbı¯) Pl. of lobus. ebellum is in a loop with the cerebral lobitis (lo¯-bı¯Јtı˘s) [Љϩitis, inflamma- cortex and is concerned with muscle co- tion] Inflammation of a lobe. ordination and cybernetic adjustment of lobo Combining form meaning lobe. movements. The flocculonodular lobe or Loboa loboi (lo¯-bo¯Јa˘lo¯Јbı¯) Fungus that archicerebellum is part of the vestibular causes keloidal blastomycosis (lobomy- system and is concerned with balance. cosis). It has been identified in tissues l. of cerebrum The frontal, parietal, but has not been cultured. occipital, and temporal lobes and the in- Lobo’s disease (lo¯Јbo¯z) [Jorge Lobo, sula or island of Reil (central lobe). 20th Cent. Brazilian physician] Lobo- flocculonodular l. The lobe of the mycosis. cerebellum consisting of the flocculi, lobomycosis (lo¯Љbo¯-mı¯-ko¯Јsı˘s) [(Lacazia) nodulus, and their connecting pedun- loboi ϩЉ] A fungal infection of the cu- cles. taneous and subcutaneous tissues in frontal l. The anterior part of a ce- which nodules resembling keloids, rebral hemisphere in front of the central plaques or warts form on the skin. It is fissure and above the lateral (Sylvian) caused by Lacazia loboi and typically fissure. found in tropical climes of South or Cen- hepatic l. A lobe of the liver. tral America. Treatment is surgical. limbic l. The marginal section of a ce- SYN: Lobo’s disease. rebral hemisphere on the medial aspect. lobotomy (lo¯-bo˘tЈo¯-me¯) [Gr. lobos, lobe, SYN: gyrus fornicatus. ϩ tome, incision] The incision of a lobe l. of lungs One of the large divisions of the brain or the lung. of the lungs: superior and inferior lobes Lobstein’s disease (lo¯bЈstı¯nz) [John of the left lung; superior, middle, and in- Georg Friedrich Lobstein, Ger. surgeon, ferior lobes of the right lung. 1777–1835] Osteogenesis imperfecta. l. of mammary gland One of the 15 lobular (lo˘bЈu¯-la˘r) [L. lobulus, small to 20 divisions of the glandular tissue of lobe] Lobulate. the breast separated by connective tis- lobular capillary hemangioma The pre- sue and each possessing a duct (lobar ferred term for the skin lesion that is duct) opening via the nipple. more commonly referred to as a “pyo- occipital l. The posterior region of a genic granuloma” or “proud flesh.” cerebral hemisphere that is shaped like lobulate, lobulated (lo˘bЈu¯-la¯t, −la¯t-e˘d) a three-sided pyramid. 1. Consisting of lobes or lobules. 2. Pert. olfactory l. The olfactory bulb and to lobes or lobules. 3. Resembling lobes. tract. SYN: rhinencephalon. SEE: olfac- SYN: lobular. tory nerve for illus. lobule (lo˘bЈu¯l) [L. lobulus, small lobe] A parietal l. The division of each cere- small lobe or primary subdivision of a bral hemisphere lying beneath each pa- lobe. It is typical of the pancreas and rietal bone. major salivary glands and may be rep- posterior l. of hypophysis The pos- resented on the surface by bumps or terior portion of the pituitary gland, bulges as seen on the thyroid gland. consisting of the pars intermedia and l. of breast Subdivisions of the lobes the processus infundibuli (pars nerv- of the mammary glands. They are com- osa). posed of multiple alveoli surrounding prefrontal l. The frontal portion of tiny ducts that secrete breast milk com- the frontal lobe of the brain. ponents. The lactiferous ducts are pyramidal l. of thyroid A portion of formed from the merging of the secre- the thyroid gland extending upward tory ducts from several lobules. from the isthmus. It is extremely vari- l. of kidney Subdivision of the renal able in size. cortex consisting of a medullary ray and quadrate l. of liver An oblong eleva- surrounding nephrons. tion on the lower surface of the liver. l. of liver A roughly hexagonal struc- Riedel’s l. SEE: Riedel’s lobe. ture consisting of hepatic cells arranged temporal l. The portion of the cere- in spoke-like plates around a central bral hemisphere lying below the lateral vein; sinusoids are between the cellular fissure of Sylvius. It is continuous pos- plates. At the periphery are branches of teriorly with the occipital lobe. the hepatic artery, portal vein, and in- lobectomy (lo¯-be˘kЈto¯-me¯) [Gr. lobos, terlobular bile ducts. lobe, ϩ ektome, excision] The surgical l. of lung Physiological units of the removal of a lobe of any organ or gland. lung consisting of a respiratory bronchi- short lobelia Indian tobacco, also known collo- ole and its branches (alveolar ducts, al- standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh lobule 1360 loculated base of rh

veolar sacs, and alveoli). SYN: primary l. cruenta The bloody postpartum pulmonary l. vaginal discharge. SYN: l. rubra. paracentral l. A cerebral convolution l. purulenta Lochia alba. on the medial surface joining the upper l. rubra Lochia cruenta. terminations of the ascending parietal l. serosa A thin, watery postpartum and frontal convolutions. vaginal discharge. parietal l. One of two subdivisions of lochiometra (lo¯Љke¯-o¯-me¯Јtra˘) [Љϩme- the parietal lobe of the brain. The su- tra, uterus] Retention of lochia in the perior parietal lobule is the posterior uterus. part of the upper portion, and the infe- lochiometritis (lo¯Љke¯-o¯-me¯-trı¯Јtı˘s) [Љϩ rior parietal lobule is a lateral area con- Љϩitis, inflammation] Puerperal in- tinuous with temporal and occipital flammation of the uterus. lobes. lochiorrhagia (lo¯Јke¯-o¯-ra¯Јje¯-a˘) [Љϩ primary pulmonary l. Lobules of lung. rhegnynai, to break forth] Excessive l. of testis Pyramidal divisions sep- flow of lochia. arated from each other by incomplete lochiorrhea (lo¯Љke¯-o¯-re¯Јa˘) [Љϩrhoia, partitions called septa. Each consists of flow] Abnormal flow of lochia. one to three coiled seminiferous tubules. lochioschesis (lo¯Љke¯-o˘sЈke˘-sı˘s) [Љϩ lobus (lo¯Јbu˘s) pl. lobi [L.] Lobe. schesis, retention] Retention or sup- LOC 1. levels of consciousness. 2. loss of pression of the lochia. consciousness. loci [L.] Pl. of locus. local (lo¯Јka˘l) [L. locus, place] Limited to lock, saline An intravenous portal, usu- one place or part. ally placed and left in a vein in one of Ј localization (lo¯-ka˘l-ı˘-za¯ shu˘n) 1. Limi- the patient’s arms, that is used episod- tation to a definite area. 2. Determina- ically for fluid or medication infusions. tion of the site of an infection. 3. Rela- Salt water flushes are used to maintain tion of a sensation to its point of origin. its patency. Saline locks replaced hepa- cerebral l. Determination of centers rin locks in the 1990s because of cost of various faculties and functions in par- and efficacy, and the latter posed a rare ticular parts of the brain. Ј but unacceptable risk of heparin-related localized (lo¯ ka˘l-ı¯zd) Restricted to a lim- allergies (esp. heparin-related throm- ited region. Ј Љ bocytopenia). localizer (lo¯ ka˘l-ı˘ ze˘r) An apparatus locked-in state A paralytic condition, su- used for finding foreign bodies or exact perficially resembling coma, in which a anatomical locations during radiogra- person has no voluntary control over so- phy. matic muscles but nonetheless remains local radiation injury An acute radiation awake and alert. The locked-in state is exposure involving a limited part of the usually the result of a lesion of the body, esp. the hands, after picking up an brainstem, esp. the pons. Because in unshielded radioactive element. The ex- some patients eye blinking is preserved, posure usually results in delayed skin communication with locked-in patients damage and frequently in underlying is occasionally possible. SYN: locked-in tissue injury. It may require local syndrome. SEE: akinetic mutism. wound care, de´bridement, or in some in- stances amputation. locked-in syndrome Locked-in state. local reaction A reaction occurring at the Locke’s solution, Locke-Ringer’s solution point of stimulation or injection of for- (lo˘ks) [Frank S. Locke, Brit. physician, eign substances. 1871–1949; Sydney Ringer, Brit. phys- locator (lo¯Јka¯-te˘r) A device for locating iologist, 1835–1910] A solution used in or discovering an object such as a for- experiments in physiology. It contains eign body. sodium, potassium, calcium, and mag- lochia (lo¯Јke¯-a˘) [Gr. lochia] The puer- nesium chlorides; sodium bicarbonate, dextrose, and water. peral discharge of blood, mucus, and tis- Ј sue from the uterus. The character of lockjaw (lo˘k ja˘w) Tonic spasm of mus- the discharge progresses through three cles of jaw. SEE: tetanus; trismus. Љ Ј stages as the normal autolytic healing locomotion (lo¯ ko¯-mo¯ shu˘n) [L. locus, ϩ process proceeds: 1) lochia rubra or place, movere, to move] Movement cruenta: For the first 2 to 4 days, the dis- or the capacity to move from one place charge is distinctly blood-tinged. 2) lo- to another. chia serosa: Between days 7 and 10, the locomotor (lo¯Љko¯-mo¯Јtor) Pert. to loco- woman usually exhibits a serous pink motion. discharge. 3) lochia alba or purulenta: locoweed (lo¯Јko¯-we¯d) A poisonous plant On or about the 10th postpartum day, from the bean family that causes behav- the discharge becomes white. An offen- ioral, visual, and gait disturbances, usu- sive odor indicates contamination by ally in cattle. saprophytic organisms. lochial (−a˘l), adj. locular (lo˘kЈu¯-la˘r) [L. loculus, a small l. alba The white postpartum vaginal space] Loculated. discharge that is no longer blood-tinged. loculated (lo˘kЈu¯-la¯t-e˘d) Containing or short SYN: l. purulenta. divided into loculi. standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh loculus 1361 longus base of rh loculus (lo˘kЈu¯-lu˘s)pl. loculi [L.] A small names, places, dates, or other practical space or cavity. and useful information. locum tenens (lo¯Јku˘mte˘nЈe˘ns) [L. locus, logoklony (lo˘gЈo¯-klo˘n-e¯) [Љϩklonein, place, ϩ tenere, to hold] A substitute; to agitate] Intermittent repetition of a physician who temporarily substitutes the last syllable of a word. for another. logokophosis (lo˘gЉo¯-ko¯-fo¯Јsı˘s) [Љϩko- locus (lo¯Јku˘s) pl. loci [L. locus, a place] phosis, deafness] Wernicke’s aphasia. 1. A spot or place. 2. In genetics, the site logopathia (lo˘g-o¯-pa˘thЈe¯-a˘) [Љϩpa- of a gene on a chromosome. thos, disease, suffering] Any disorder of l. ceruleus A central nervous system speech arising from derangement of the nucleus on either side of the midline un- central nervous system. der the fourth ventricle in the pontine logoplegia (lo˘g-o¯-ple¯Јje¯-a˘) [Љϩplege, part of the brainstem. This small nu- stroke] Paralysis of the speech organs. cleus contains pigmented neurons that logorrhea (lo˘gЉo¯-re¯Јa˘) [Љϩrhoia, flow] send noradrenergic axons unusually Repetitious, continuous and excessive widely, throughout the brain, and may speech. It may be a symptom of mania play a key role in broad cortical activa- or some forms of intoxication. tion from the reticular formation of the logospasm (lo˘gЈo¯-spa˘zm) [Љϩspas- brainstem. mos, a convulsion] Spasmodic word l. of control A term used in reference enunciation. to an individual’s sense of mastery or log phase (lo˘g) [From log(arithm)] That control over events. Persons with an in- portion of the bacterial growth curve at ternal locus of control are more apt to which bacteria are reproducing at an ex- believe that they can influence events, ponential rate. whereas those with an external locus of -logy [Gr. logos, word, reason] Combin- control tend to believe that events are ing form used as a suffix meaning sci- dictated by fate. These respective ori- ence or study of. SEE: -ology. entations can influence a person’s prac- loiasis (lo¯-ı¯Јa˘-sı˘s) Infection with the Af- tice of health-related behaviors. rican eyeworm, Loa loa. SYN: Loiasis. LOD Limit of detection. SEE: Loa loa for illus. Loeffler’s bacillus (le˘fЈle˘rz) [Friedrich loin (loyn) [O.Fr. loigne, long part] The August Johannes Loeffler (Loffler), Ger. lower part of the back and sides between bacteriologist, 1852–1915] Corynebac- the ribs and pelvis. SEE: lumbus. terium diphtheriae. loneliness The anxious, depressed, or Lo¨ffler’s endocarditis (le˘fЈle˘rz) [Wilhelm dysphoric mood that occurs as a result Lo¨ffler, Swiss physician, 1887–1972] of physical or psychic isolation. Endocarditis associated with hypereo- risk for l. The risk for experiencing sinophilia and fibroplastic thickening of discomfort associated with a desire or the endocardium. need for more contact with others. SEE: Lo¨fgren’s syndrome (le˘fЈgre˘nz, lo¨fЈ)A Nursing Diagnoses Appendix. type of sarcoidosis characterized by ex- long-acting thyroid stimulator ABBR: tensive involvement of hilar lymph LATS. An IgG autoantibody that binds nodes, erythema nodosum, and joint to the thyroid-stimulating hormonecep- pains, esp. around the ankles. The syn- tor, stimulating the excessive produc- drome has a better prognosis than other tion of thyroid hormones and causing forms of sarcoidosis. hyperthyroidism. This immunoglobulin log A continuously kept record of impor- is found in the blood of about 75% of pa- tant events, such as medical records or tients with Graves’ disease but is used progress notes. rarely for diagnostic purposes, because -log [Gr. logos, word, reason] Combining the diagnosis usually can be established form meaning words or speech. on clinical grounds, i.e., on finding a pa- logagnosia (lo˘gЉa˘g-no¯Јse¯-a˘) [Gr. logos, tient with hyperthyroidism with a dif- word, reason, ϩ a-, not, ϩ gnosis, fuse, nontender goiter, exophthalmos, knowledge] A type of aphasia in which and/or pretibial myxedema. words are seen but not identified with longevity (lo˘n-je˘vЈı˘-te¯) [L. longaevus, respect to their meaning. SEE: aphasia. aged] Long duration of life. logagraphia (lo˘g-a˘-gra˘fЈe¯-a˘) [ЉϩЉϩ longing A persistent desire or craving for graphein, to write] Agraphia. something, usually that which is remote logamnesia (lo˘g-a˘m-ne¯Јze¯-a˘) [Љϩam- or unattainable. nesia, forgetfulness] Inability to recog- longissimus (lo˘n-jı˘sЈı˘-mu˘s) [L.] An an- nize or make sense of spoken or written atomical term indicating a long struc- words. ture. logaphasia (lo˘gЉa˘-fa¯Јze¯-a˘) [Љϩa-, not, longitudinal (lo˘nЉjı˘-tu¯ Јdı˘-na˘l) [L. longi- ϩ phasis, speaking] Motor aphasia, tudo, length] Parallel to the long axis usually the result of a cerebral lesion. of the body or part. logasthenia (lo˘gЉa˘s-the¯Јne¯-a˘) [ЉϩЉϩ longsightedness (lo˘ngЈsı¯tЉe˘d-ne˘s) Hy- sthenos, strength] Inability to under- peropia. stand the spoken word. longus (lo˘ngЈgu˘s) [L.] An anatomical short log book A diary; a register of important term indicating a long structure. standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh look-alike/sound-alike drugs 1362 loupe base of rh look-alike/sound-alike drugs Medica- LOP left occipitoposterior fetal position. tions with drug names that look similar SEE: presentation for illus. in print or sound similar to other drugs lophotrichous (lo˘f-o˘tЈrı˘-ku˘s) Having when their names are spoken. Such bunches of flagella at one end. agents carry a significant risk of being LOQ limit of quantitation. administered improperly, esp.when ex- lorazepam (lo¯-ra¯Јze˘-pam) A relatively changed for one another. short-acting benzodiazepine used to lookback A colloquial term for retrospec- treat anxiety, insomnia, seizures, and tive research, that is, for any investi- alcohol withdrawal. gation that attempts to review the un- lordoscoliosis (lorЉdo¯-sko¯Љle¯-o¯Јsı˘s) [Gr. derlying causes of an event. lordosis, bending, ϩ skoliosis, curva- loop [ME. loupe] A curve or bend in a tion] Forward curvation of the spine cord or cordlike structure, forming complicated by lateral curvature. roughly an oval. lordosis (lor-do¯Јsı˘s) [Gr.] Abnormal an- l. of capillary Minute blood vessels in terior convexity of the lumbar spine. the papillae of the dermis. Lorenzo’s oil (lo˘-re˘nЈzo¯z) A mixture of cervical l. The part of an enamel or- two fats (glyceryl-trioleate and glyceryl- gan in which the inner enamel epithe- trierucate) used to treat neurological lium is continuous with the outer disorders, including adrenoleukodystro- enamel epithelium. This establishes the phy. limit of enamel formation and therefore losartan (lo¯-sa˘rЈta˘n) An antihyperten- represents the site of the cementoena- sive and angiostensin II receptor antag- mel junction. The cells of the cervical onist, administered orally to manage loop become Hertwig’s epithelial root hypertension. SYN: Cozaar. sheath, induce dentinogenesis, and de- loss 1. The basis of claim on the part of a termine the number, size, and shape of party to a lawsuit or an insurance car- the tooth roots. rier. 2. Destruction, degeneration, or closed l. 1. A biological system in the wasting of cells, tissues, organs, or which a substance produced affects the capabilities. output of the substance by a feedback insensible l. A loss of body fluid that mechanism. 2. In the learning of motor is not easily measured (e.g., the mois- skills, the process of using sensory feed- ture released in exhalation and perspi- back to modify fine motor control or ration). skilled movements. sensible l. A measurable loss of body flow-volume l. A graphic record of fluid (e.g., blood, diarrhea, urine, lung function in which the amount of vomit). If sensible losses consistently gas inhaled and exhaled is recorded on exceed fluid intake, dehydration may re- the horizontal axis and the rate at sult. which the gas moves on the vertical loss, bone Osteoporosis. axis. It is used to detect abnormalities loss of consciousness Syncope. in pulmonary function such as those ac- lost to follow-up In clinical medicine and companying restrictive or obstructive research, a person who has not returned lung disease. Henle’s l. SEE: under Henle, Fried- for continued care or evaluation (e.g., rich G.J. because of death, disability, relocation, Lippes l. SEE: Lippes loop. or drop-out). loop electrosurgical excision procedure LOT left occipitotransverse fetal position. ABBR: LEEP. A technique for resect- SEE: presentation for illus. Lotensin SEE: benazepril. ing abnormal tissue of the cervix. An Ј electrical current is passed through a lotion (lo¯ shu˘n) [L. lotio] A liquid me- thin wire loop that acts as a scalpel, re- dicinal preparation for local application moving a thin layer of tissue suitable for to, or bathing of, a part. histological evaluation. lot number An identifier assigned to a loose body A fragment of bone or carti- batch of medications. It facilitates drug lage within the joint of a patient with manufacturing inventory control and severe degenerative or neuropathic ar- tracing adverse incidents in a batch of thritis. contaminated medications. loosening (loosЈı˘n-ı˘ng) 1. Loss of linkage LOTR Licensed Occupational Therapist. with or fixation to another structure. loudness The perceived intensity of 2. In speech, loss of connection to the sound. It often reflects the amplitude usual rules of grammar, diction, or rea- and frequency of a sonic stimulus, but son. because it varies from person to person, loosening of association A sign of dis- it is a subjective, rather than a purely ordered thought processes in which the measurable entity. SEE: decibel. person speaks with frequent changes of Louis-Bar syndrome (loo-we¯Јba˘r) [Den- subject, and the content is only ise Louis-Bar, 20th century Belgian obliquely related, if at all, to the subject neuropathologist] Ataxia-telangiecta- matter. This may be seen in mania or sia. short schizophrenia. loupe (loop) [Fr.] A magnifying lens standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh louse 1363 lubricant base of rh

used in the form of a monocular or bin- slanting, ϩ arthron, joint] Oblique ocular lens. Surgeons, dentists, jewel- deformity of a joint without dislocation. ers, and watchmakers frequently use loxia (lo˘ksЈe¯-a˘) [Gr., slanting] Torticol- this device. lis. louse [AS. lus] Pediculus. Loxosceles (lo˘ks-o˘sЈse˘-le¯z) A genus of body l. Pediculus humanus corporis. spiders, family Loxoscelidae, which in- crab l. Phthirus inguinalis and cludes the brown recluse spider. Phthirus pubis; the louse that infests loxoscelism (lo˘k-so˘sЈse˘-lı˘zm) The dis- the pubic region and other hairy areas ease produced by the bite of the brown of the body. SEE: pediculosis. recluse spider, Loxosceles laeta or L. re- head l. Pediculus humanus capitis. clusa. Symptoms include a painful red SEE: illus. vesicle that eventually becomes ne- crotic, leaving a skin ulcer. Rarely, the spider bite may produce hemolytic ane- mia or renal failure. loxotomy (lo˘ks-o˘tЈo¯-me¯) [Љϩtome, in- cision] Amputation by oblique section. lozenge (lo˘zЈe˘nj) [Fr.] A small, dry, me- dicinal solid to be held in the mouth un- til it dissolves. SYN: troche. zinc gluconate l., zinc gluconate gly- cine A dietary supplement marketed as a means of diminishing the duration of symptoms of the common cold (e.g., sore throat, nasal congestion). It is also used to alleviate stomach upset. Large doses may cause nausea or vomiting. It has a bitter, metallic taste. Lp(a) lipoprotein (a). L-phase variants L-forms. LPO left posterior oblique position. Lr Symbol for the element lawrencium. LRF luteinizing hormone releasing factor. LSA left sacroanterior fetal position. SEE: presentation for illus. LScA left scapuloanterior fetal position. SEE: presentation for illus. LScP left scapuloposterior fetal position. SEE: presentation for illus. LSD lysergic acid diethylamide. LSI life satisfaction index. LOUSE LSP left sacroposterior fetal position. L/S ratio lecithin/sphingomyelin ratio. love [ME.] 1. Profound concern and af- LST left sacrotransverse fetal position. fection for another person. 2. In psycho- LTBI An abbreviation for latent tubercu- analysis, love may be equated with plea- losis infection. Active tuberculosis may sure, particularly as it applies to the emerge in patients who have latent (in- gratifying sexual experiences between active) infections when their immune individuals. systems fail, either because of malnu- Love´n’s reflex (lo¯-va¯nzЈ) [Otto Christian trition, or because they contract other Loven, Swed. physician, 1835–1904] co-morbid diseases. A goal of worldwide Vasodilation with a corresponding in- public health institutions is the eradi- crease in blood pressure in an organ, re- cation of latent tuberculosis infection sulting from stimulation of an afferent from the more than 2 billion infected nerve. persons around the globe. low birth weight SEE: under weight. LTC long-term care. low-energy emission therapy ABBR: LTH luteotropic hormone. SEE: under LEET. An alternative treatment for hormone. sleep disorders in which the oral mu- Lu Symbol for the element lutetium. cosa is stimulated by low-wattage elec- lubb-dupp (lu˘b-du˘pЈ) The two sounds tromagnetic fields. heard in auscultation of the heart tech- low intensity laser therapy Any of sev- nically referred to as S1 (“lubb”) and S2 eral lasers that cause photochemical (“dupp”). The pause following the changes in body tissues without produc- sounds is slightly longer than that be- ing thermal changes. tween the two sounds. SEE: ausculta- low-level radiation SEE: radiation, low- tion. level. lubricant (looЈbrı˘-ka˘nt) [L. lubricans] lox (lo˘ks) liquid oxygen. An agent, usually a liquid oil, that re- short loxarthron (lo˘ks-a˘rЈthro˘n) [Gr. loxos, duces friction between parts that brush standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh lucent 1364 lumbar base of rh

LUMBAR PUNCTURE

against each other as they move. Joints lues (lu¯ Јe¯z) [L.] Syphilis. are lubricated by synovial fluid. luetic (lu¯-e˘tЈı˘k) Syphilitic. lucent (looЈse˘nt) [L. lucere, to shine] Lugol’s solution (lu¯ Јgo˘lz) [Jean G. A. Lu- Shining, translucent, clear. gol, Fr. physician, 1786–1851] A strong lucid (lu¯ Јsı˘d) [L. lucidus, clear] Clear, iodine solution used in iodine therapy, esp. applied to clarity of the mind. consisting of iodine 5 g, potassium iodide l. interval SEE: under interval. 10 g, and water to make 100 ml. lucidity (lu¯-sı˘dЈı˘-te¯) The quality of clear- LUL left upper lobe (of the lung). ness or brightness, esp. with regard to lumbago (lu˘m-ba¯Јgo¯) [L. lumbus, loin] mental conditions. A general nonspecific term for dull, ach- luciferase (loo-sı˘fЈe˘r-a¯s) An enzyme that ing pain in the lumbar region of the acts on luciferins to oxidize them and back. SYN: lumbodynia. cause bioluminescence. It is present in lumbar (lu˘mЈba˘r) [L. lumbus, loin] Pert. certain organisms (e.g., fireflies, other to the loins (the part of the back be- insects) that emit light either continu- tween the thorax and pelvis). ously or intermittently. l. puncture Gaining entry into the luciferin (loo-sı˘fЈe˘r-ı˘n) The general term subarachnoid space of the meningeal for substances present in some orga- sac below the end of the spinal cord, nisms, which become luminescent when usually at the level of the fourth inter- acted on by luciferase. vertebral space with a hollow needle. lucifugal (loo-sı˘fЈu¯-ga˘l) [L. lux, light, ϩ This procedure is done to obtain cere- fugere, to flee from] Repelled by bright brospinal fluid (CSF) for analysis (e.g., light. in the diagnosis of severe headache or Lucilia sericata (loo-sı˘lЈe¯-a˘se˘r-ı˘-ka¯tЈa˘) in suspected central nervous system in- [NL] The sheep blowfly, also known as fection or bleeding); to administer drugs the green bottlefly. It is a cause of my- to the brain or spinal cord (e.g., anes- iasis in humans. Sterile maggots of this thetics or chemotherapeutic agents); or species are necrophagous and have been to relieve the CSF of excess pressure or used to debride wound infections. fluid (e.g., in pseudotumor cerebri). lucipetal (loo-sı˘pЈı˘-ta˘l) [Љϩpeter, to SYN: puncture, spinal Quincke’s punc- seek] Attracted by bright light. ture. SEE: illus.; cisternal puncture; Ludwig’s angina (lu¯dЈvı˘gz) [Wilhelm F. headache; Queckenstedt’s sign. von Ludwig, Ger. surgeon, 1790–1865] A suppurative inflammation of subcu- taneous connective tissue adjacent to a Postprocedure headache occurs in submaxillary gland. about half of all patients who un- short L.U.E. left upper extremity. dergo lumbar puncture. Rarely reported standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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LUMBAR PUNCTURE complications of the procedure include ce- privacy. Next, the patient’s skin is pre- rebral herniation, epidural infection, epi- pared with antiseptic solution and a dural bleeding, paraparesis, and subdural sterile fenestrated barrier placed over bleeding. the proposed puncture site. Local anes- thetic is injected, and then the spinal needle, with its stylet in place, is slowly PROCEDURE: Informed consent for the procedure is obtained, except in dire advanced between the vertebra to and emergencies, when clinical judgment through the dura and arachnoid mem- prevails. Appropriate equipment is branes. The stylet that fills the needle gathered: sterile gloves and mask for is removed and initial measurements the operator, skin antiseptic (povidine- are made of the opening intracranial iodine solution), local anesthetic (1% pressure (ICP) with a manometer. lidocaine), and a lumbar puncture tray When the procedure is performed for di- containing sterile gauze sponges, fen- agnosis, about 8 to 10 ml of fluid are col- estrated drape and towel, needles and lected and sent promptly to the clinical syringe for anesthesia, spinal needles, 4 laboratory for analysis of cell count, glu- collection tubes, 3-way stopcock and cose, protein levels, cultures stains and manometer; and a small adhesive band- special studies. The closing pressure age. should then be read, the needle re- The procedure and expected sensa- moved, and a small impervious adhe- tions are explained, and the patient is sive dressing applied, sometimes with asked to remain still when positioned collodion to prevent CSF leakage. SEE: and to breathe normally. The patient is illus. typically placed on his left side at the COMPLICATIONS: Pain at the punc- right edge of the bed or examining table ture site, infection, bleeding, neurologi- with knees drawn up to the abdomen cal injury, death, and post–spinal tap and chin down to the chest; or in a sit- headaches are all potential complica- ting position with legs over one side of tions. Of these, postural headache, the table and buttocks at the other, caused by chronic leakage from the bending head and chest toward the puncture site, is the complication most knees. Either of these positions exposes often brought to the attention of health the back to the operator and provides care professionals. It may be treated spinal flexion, allowing easy access to with the injection of a small amount of the lumbar subarachnoid space. The as- the patient’s own blood epidurally, to sisting nurse holds the patient appro- form a “blood patch.” SEE: fluid, cere- priately to secure this position (one arm brospinal. around the neck, the other around the PATIENT CARE: The nurse assists knees, or holding both shoulders bent the operator as necessary throughout short forward). Draping provides warmth and the procedure by numbering and cap- standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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ping specimen tubes for laboratory ex- name for Ascaris lumbricoides. 2. An amination and by applying jugular vein earthworm. pressure as directed. Reassurance and lumen (lu¯ Јme˘n) pl. lumina [L., light] direction are provided to the patient 1. The space within an artery, vein, in- throughout the procedure, and the pa- testine, or tube. 2. A unit of light, the tient is assessed for adverse reactions amount of light emitted in a unit solid (elevated pulse rate, pain radiating into angle by a uniform point source of one the limbs, pallor, clammy skin, or res- international candle. SEE: light unit; piratory distress). candela. After the procedure, the nurse as- luminal (lu¯ Јmı˘-na˘l) Relating to the lu- sesses vital signs and neurological men of a tubular structure, such as a status, particularly observing for signs blood vessel. of paralysis, weakness, or loss of sen- luminescence (looЉmı˘-ne˘sЈe˘ns) 1. Pro- sation in the lower extremities. If CSF duction of light without production of pressure is elevated, the patient’s neu- heat. SEE: bioluminescence. 2. In radi- rological status should be assessed ology, the light produced by a fluores- every 15 min for 4 hr, if normal, every cent phosphor when exposed to radia- hour for 2 hr, then every 4 hr or as or- tion. dered. The puncture site should be luminiferous (looЉmı˘-nı˘fЈe˘r-u˘s) [L. lu- checked hourly for 4 hr, then every 4 hr men, light, ϩ ferre, to bear] Producing for 24 hr, assessing for redness, swell- or conveying light. ing, and drainage. To decrease the luminometer (loo-mı˘n-o˘mЈe˘-te˘r) A lu- chance of headache, oral intake (for spi- minescence photometer used to assay nal fluid replacement and equalization chemluminescent and bioluminescent of pressures) is encouraged, and the pa- reactions. It is used clinically to assay tient should remain in bed in a supine for bacteria and living cells. position or with the head elevated no luminophore (looЈmı˘-no¯-forЉ)[ЉϩGr. more than 30Њ for 4 to 24 hr (per oper- phoros, bearing] A chemical present in ator or institutional protocol). The pa- organic compounds that permits lumi- tient should not lift his head but can nescence of those compounds. move it (and himself) from side to side. luminous (looЈmı˘-nu˘s) Emitting light. Noninvasive pain relief measures and lumirhodopsin (looЉmı˘-ro¯-do˘pЈsı˘n) A prescribed analgesia are provided if chemical in the retina of the eye, inter- headache occurs. mediate between rhodopsin and all- l. region That area of the abdominal trans-retinal plus opsin, formed during surface lateral to the umbilical region, the bleaching of rhodopsin by exposure above the iliac region, and below the hy- to light. pochondriac region. lumpectomy (lu˘m-pe˘kЈto¯-me¯) [lump ϩ lumbarization (lu˘mЉba˘r-ı˘-za¯Јshu˘n) Non- Gr. ektome, excision] Surgical removal fusion of the first sacral vertebra with of a tumor from the breast, esp. to re- the sacrum, therefore functioning as an move only the tumor and no other tissue additional (sixth) lumbar vertebra. or lymph nodes. lumbo- [L. lumbus, loin] Combining lunar (loonЈe˘r) Pert. to the moon, a form meaning loins. month, or silver. lumbocolostomy (lu˘mЉbo¯-ko¯-lo˘sЈto¯-me¯) lunate (loo-na¯t) 1. Moon-shaped or cres- [ЉϩGr. kolon, colon, ϩ stoma, cent. 2. A bone in the proximal row of mouth] Colostomy by lumbar incision. the carpus. SYN: semilunar bone. lumbocostal (lu˘mЉbo¯-ko˘sЈta˘l) [Љϩlung (lu˘ng) [AS. lungen] One of two costa, rib] Relating to the loins and cone-shaped spongy organs of respira- ribs. tion contained within the pleural cavity lumbodynia (lu˘mЉbo¯-dı˘nЈe¯-a˘) [ЉϩGr. of the thorax. SEE: illus.; alveolus for il- odyne, pain] Lumbago. lus. lumbosacral (lu˘mЉbo¯-sa¯Јkra˘l) Pert. to ANATOMY: The lungs are connected the lumbar vertebrae and the sacrum. with the pharynx through the trachea lumbrical (lu˘mЈbrı˘-ka˘l) [L. lumbricus, and larynx. The base of each lung rests earthworm] Vermiform. on the diaphragm, and each lung apex lumbricalis (lu˘mЉbrı˘-ka˘lЈı˘s) One of the rises from 2.5 to 5 cm above the sternal worm-shaped muscles of the hand or end of the first rib, the collarbone, sup- foot. ported by its attachment to the hilum or lumbricide (lu˘mЈbrı˘-sı¯d) [Љϩcaedere, root structures. The lungs include the to kill] An agent that kills lumbricoid lobes, lobules, bronchi, bronchioles, al- worms (i.e., ascarides or intestinal veoli or air sacs, and pleural covering. worms). The right lung has three lobes and the lumbricosis (lu˘mЉbrı˘-ko¯Јsı˘s) [ЉϩGr. left two. In men, the right lung weighs osis, condition] The state of being in- approx. 625 g, the left 570 g. The lungs fested with lumbricoid worms. contain 300,000,000 alveoli and their Lumbricus (lu˘m-brı¯Јku˘s) A genus of respiratory surface is about 70 sqm. worms that includes earthworms. Respirations per minute are 12 to 20 in short lumbricus (lu˘m-brı¯Јku˘s) 1. An obsolete an adult. The total capacity of the lung standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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ARTERIOLE PULMONARY CAPILLARIES FRONTAL SINUSES ALVEOLAR DUCT SPHENOIDAL SINUSES NASAL CAVITY NASOPHARYNX

SOFT PALATE

EPIGLOTTIS

LARYNX AND VOCAL FOLDS ALVEOLUS

TRACHEA VENULE SUPERIOR LOBE B RIGHT LUNG LEFT LUNG RIGHT PRIMARY BRONCHUS LEFT PRIMARY BRONCHUS

MIDDLE LOBE SUPERIOR LOBE

BRONCHIOLES

INFERIOR LOBE

INFERIOR LOBE MEDIASTINUM PLEURAL MEMBRANES DIAPHRAGM CARDIAC NOTCH PLEURAL SPACE A LUNGS (A) anterior view of upper and lower respiratory tracts, (B) alveoli and pulmonary capillaries

varies from 3.6 to 9.4 L in men and 2.5 are separated only by the cell of the al- to 6.9 L in women. veolus and that of the pulmonary cap- The left lung has an indentation, illary. This respiratory membrane is called the cardiac depression, for the thin (0.07 to 2.0 ␮m) and permits oxy- normal placement of the heart. Behind gen to diffuse into the blood and carbon this is the hilum, through which the dioxide to diffuse from the blood to the blood vessels, lymphatics, and bronchi air. enter and leave the lung. NERVE SUPPLY: The lungs are in- Air travels from the nasal passages to nervated by parasympathetic fibers via the pharynx, larynx, and trachea. Two the vagus nerve and sympathetic fibers primary bronchi, one on each side, ex- from the anterior and posterior pulmo- tend from the trachea. The primary nary plexuses to the smooth muscle in bronchi divide into secondary bronchi, the walls of the bronchial tree. one for each of five lobes. These further BLOOD VESSELS: The bronchial ar- divide into a great number of smaller teries and veins circulate blood to the bronchioles. The pattern of distribution bronchial tree. The pulmonary arteries of these into the segments of each lobe and veins circulate the blood involved in is important in pulmonary and thoracic gas exchange. surgery. There are about 10 broncho- FUNCTION: The primary purpose of pulmonary segments in the right lung the lung is to bring air and blood into and eight in the left, the actual number intimate contact so that oxygen can be varying. There are 50 to 80 terminal added to the blood and carbon dioxide bronchioles in each lobe. Each of these removed from it. This is achieved by two divides into two respiratory bronchioles, pumping systems, one moving a gas and which in turn divide to form two to 11 the other a liquid. The blood and air are alveolar ducts. The alveolar sacs and al- brought together so closely that only ap- veoli arise from these ducts. The spaces prox. 1 ␮m (10Ϫ6 m) of tissue separates between the alveolar sacs and alveoli them. The volume of the pulmonary cap- are called atria. illary circulation is 150 ml, but this is short In the alveolus, blood and inspired air spread out over a surface area of approx. standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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750 sqft (69.68 sqm). This capillary times over a lung compressed by a mod- surface area surrounds 300 million air erate effusion. sacs called alveoli. The blood that is low Harsh inspiratory sounds are typical in oxygen but high in carbon dioxide is of stridor, a medical emergency. Expi- in contact with the air that is high in rations that are prolonged and musical oxygen and low in carbon dioxide for are characteristic of wheezing. less than 1 second. SEE: respiratory de- Friction: This sound is produced by fense function. the rubbing together of roughened pleu- PHYSICAL EXAMINATION: Inspec- ral surfaces. It may be heard in both in- tion: The examiner determines the res- spiration and expiration. Friction often piratory rate by unobtrusively watching resembles crackle, but is more superfi- the patient’s chest rise and fall and cial and localized than the latter and is counting the number of breaths per not modified by cough or deep inspira- minute. In adults a normal respiratory tion. rate at rest is about 12 breaths per min- Metallic tinkling: A silvery bell-like ute. While counting the respiratory sound heard at intervals over a hydro- rate, the examiner can observe other pneumothorax or large cavity. Speak- breathing characteristics. Dyspneic pa- ing, coughing, and deep breathing usu- tients breathe rapidly, often laboring to ally induce this sound. It must not be draw breath even when at rest. Retrac- confused with a similar sound produced tions of the intercostal and supraclavic- by liquids in the stomach. ular spaces are visible during inspira- Crackles: Abnormal bubbling sounds tion. Sleep apnea is characterized by heard in air cells or bronchi. episodes of stalled breathing followed by Succussion-splash or hippocratic suc- periods of respiratory compensation. cussion: A splashing sound produced by Regular slow breathing is normal. the presence of air and liquid in the Palpation: In health, the chest and chest. It may be elicited by gently shak- lung transmit a vibration, called fremi- ing the patient during auscultation. tus, during speech. Fremitus abnormal- This sound nearly always indicates ei- ities may be felt in chronic obstructive ther a hydropneumothorax or a pyo- lung diseases or obesity, in which the vi- pneumothorax, although it has also bration is diminished, and in pneumo- been detected over very large cavities. nia, in which it is increased over the in- The presence of air and liquid in the fected lobe. stomach produces similar sounds. Percussion: Tapping on the chest wall bird breeder’s l. An allergic (hyper- over healthy lung results in a hollow sensitivity) inflammation of the lung resonant sound. The hollow character of caused by exposure to bird excreta. In the resonance sometimes is exaggerated some patients the onset is slow rather than acute. Symptoms, which include in emphysematous lungs or in pneu- chills, fever, cough, and shortness of mothorax, and muffled by pleural effu- breath, usually subside when exposure sions or pulmonary consolidation. to the antigen ceases. SYN: pigeon AUSCULTATION: Normal breath breeder’s disease. SEE: psittacosis. sounds: In the healthy person, breath black l. Lay term for the chronic lung sounds are low-pitched and have a fre- disease or pneumoconiosis found in coal quency of 200 to 400 cycles per second miners. SYN: coal worker’s pneumoco- (cps); frequency rarely exceeds 500 cps. niosis. These sounds are called vesicular blast l. The shredding-type effect breath sounds when heard over the that takes place in the alveolar surfaces lungs. They are produced by air passing of the lung caused by the shock of an in and out of the airways. explosion or blast, which can cause al- Bronchial and tracheal breath veolar contusion. sounds: These are higher-pitched and brewer’s l. An allergic respiratory louder than vesicular sounds, and are condition caused by the mold Aspergil- produced by air passing over the walls lus. of the bronchi and trachea. These cobalt l. Hard metal disease. sounds are normally heard only over the compliance of l. A measure of the bronchi and trachea. distensibility of the lungs. It is ex- Amphoric and cavernous breathing: pressed as the change in volume of the These two nearly identical sounds are lungs in liters when the transpulmo- loud, with a prolonged, hollow expira- nary pressure is changed by 1 cm of wa- tion. The pitch of amphoric breathing is ter pressure. Normally this measure is slightly higher than that of the cavern- between 0.08 and 0.33 L/cm of water. It ous type, and may be imitated by is reduced by abnormalities that stiffen blowing over the mouth of an empty jar. the lungs or chest wall. It is heard in bronchiectatic cavities or flock worker’s l. Interstitial lung dis- pneumothorax when the opening to the ease that results from the inhalation of lung is patulous; in the consolidation airborne nylon fibers at work. Nylon fi- short area near a large bronchus; and some- bers, which can cause inflammatory standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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damage to the lungs, are used in mak- atodes that infest the lungs of humans ing products for upholstery, automo- and animals. biles, carpet, and apparel. lunula (lu¯ Јnu¯-la˘) pl. lunulae [L., little l. inflammation Pneumonia. moon] 1. A crescent-shaped area. 2. An honeycomb l. An abnormal appear- active area of nailbed growth at the base ance of the lungs seen on chest x-ray of the fingernails and toenails. The cells exam, in which small cystic spaces al- develop and keratinize to form nails. ternate with coarsely increased inter- l. of valves of heart One of two nar- stitial markings. This pattern is typical row portions on the free edges of the of pulmonary injury caused by inhala- semilunar valves on each side of the tion of dusts, minerals, toxic gases, or nodulus. fibers; rheumatological diseases; and in- lupiform (lu¯ Јpı˘-form) [L. lupus, wolf, ϩ terstitial pneumonitis. forma, shape] Resembling lupus. humidifier l. Humidifier fever. lupoid (looЈpoyd) [ЉϩGr. eidos, form, iron l. Drinker respirator. shape] 1. Resembling lupus. 2. Boeck’s oblique fissure of l. In each lung, the sarcoid. deep groove separating the bottom and lupous (lu¯ Јpu˘s) 1. Pert. to lupus. 2. Af- side of the upper lobe from the top and fected with lupus. side of the lower lobe. lupus (lu¯ Јpu˘s) [L., wolf] Originally any shock l. A diffuse lung injury, caus- chronic, progressive, usually ulcerating, ing reduced perfusion, pulmonary skin disease. In current usage, when the edema, and alveolar collapse, associated word is used alone, it has no precise with acute respiratory distress syn- meaning. drome. SYN: wet lung. discoid l. erythematosus ABBR: l. surfactant Pulmonary surfactant. DLE. A chronic skin disease character- l. transplantation Grafting of a donor ized by periodic acute appearances of a lung into a recipient with end-stage scaling, red, macular rash. DLE is lung disease, usually caused by pulmo- caused by an autoimmune process in- nary fibrosis, chronic obstructive lung volving both B-cell– and T-cell–medi- disease, or pulmonary hypertension. ated mechanisms that destroy the skin’s Lung transplantation may be per- basal cells. DLE is treated with topical formed as a single-organ operation or as corticosteroids. It is found in about 5% part of a combined heart-lung trans- to 30% of patients who have systemic lu- plantation (e.g., in congenital heart dis- pus erythematosus (SLE) (esp. those ease). Immunosuppressive therapy with who smoke) but also may occur alone cyclosporine or tacrolimus, azathio- (without other findings of SLE). SEE: prine, and corticosteroids is necessary autoimmune disease; systemic l. erythe- to minimize the risk of rejection, which matosus. TREATMENT: The patient should is caused by T lymphocyte activity avoid exposure to the sun. Skin lesions against the donor tissue. Rejection is di- should be treated with topical cortico- agnosed through the use of bronchial bi- steroids, but overuse of these prepara- opsies and pulmonary function tests. tions should be avoided. Acute rejection, characterized by dys- drug-induced systemic l. erythema- pnea, fever, hypoxemia, rales, and ta- tosus A group of signs and symptoms chypnea, must be differentiated from in- similar to those of systemic lupus ery- fection. Chronic rejection, a problem in thematosus, caused by an adverse re- 25% to 50% of cases, presents as bron- action to drugs, esp. procainamide, hy- chiolitis obliterans and occurs 6 to 14 dralazine, and isoniazid. Joint months after the transplant. Flow rates inflammation and pain, skin rash, pleu- progressively decrease, with few addi- risy, and fever are the most common tional symptoms; bronchodilator ther- manifestations; kidney and central ner- apy is not effective, and giving higher vous system involvement are rare. An- doses of immunosuppressives has tinuclear antibodies, specifically mixed success. Sixty percent of lung against the histones that fold DNA, are transplant recipients live 2 years. common. Some patients develop anti- wet l. Shock l. nuclear antibodies but do not develop lung collapse 1. Atelectasis. 2. Compres- lupus-like symptoms. The lupus-like sion of lung caused by pneumothorax, syndrome usually disappears when the hydrothorax, or hemothorax. drug causing it is discontinued. SEE: TREATMENT: Bronchial hygiene, antinuclear antibodies; systemic lupus postural drainage, and percussion are erythematosus. used to assist in mucus removal for neonatal l. Rash, abnormally low those patients with atelectasis due to platelet counts, liver and brain disease, mucus plugging. Bronchoscopy may and congenital heart block occurring in also be useful in these patients. Chest an infant whose mother has systemic lu- tubes are inserted to drain air or fluid pus erythematosus. The disease results from the pleural cavity when present. from the passage of maternal autoanti- short lungworm (lu˘ngЈwe˘rm) Any of the nem- bodies to the developing fetus. Although standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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most of the findings resolve spontane- more of the following criteria are ously, congenital heart block does not, present, either at one time or sequen- and it may require the insertion of a tially: pacemaker. 1 butterfly rash; l. panniculitis Lupus profundus. 2 raised, scaly discoid skin lesions; l. pernio Noncaseating granulomas 3 abnormal titer of antinuclear anti- occurring on the face, esp. around the bodies seen by immunofluorescence; nose, eyes, cheeks, lips, and ears. “Lu- 4 other autoantibodies (anti-Sm; se- pus” in lupus pernio is misleading be- rological tests for syphilis); cause it suggests a connection with sys- 5 pleuritis or pericarditis (together temic lupus erythematosus; lupus referred to as “serositis”); pernio is actually a finding of the skin 6 hemolytic anemia, leukopenia in sarcoidosis. (white blood cell count less than 4,000 l. profundus A deeply scarring, mm3), lymphopenia (lymphocyte count atrophic rash occasionally found in pa- less than 1,500/mm3), or thrombocyto- tients with systemic lupus erythemato- penia of less than 100,000/mm3; sus, caused by inflammation of subcu- 7 oral or nasopharyngeal ulcers; taneous fatty tissue. SYN: l. panni- 8 nonerosive arthritis; culitis. 9 psychosis or seizures without other systemic l. erythematosus ABBR: clear cause; SLE. A chronic autoimmune inflam- 10 photosensitivity skin rash; matory disease of connective tissue in- 11 proteinuria greater than 0.5 g/day volving multiple organ systems and or cellular casts in the urine. marked by periodic acute episodes. Its Some drugs can cause a lupus-like name is derived from the characteristic syndrome; the most common of these erythematous “butterfly” rash over the are procainamide, isoniazid, and hy- nose and cheeks, which resembles a dralazine. SEE: drug-induced systemic wolf’s snout, although this is present in l. erythematosus. less than 50% of patients. The disease SYMPTOMS: The onset of the disease is most prevalent in women (ratio of 8:1 may be acute or insidious. Patients have women:men) of childbearing age (ratio a wide variety of clinical symptoms, of 15:1). Although it occurs worldwide, signs, and laboratory findings, but ane- it is most prevalent among black and mia, thrombocytopenia, polyarthritis, Asian peoples. SEE: Nursing Diagnoses (polyarthralgia) skin rashes, glomeru- Appendix. lonephritis, fever, malaise, weight loss, ETIOLOGY AND PATHOLOGY: SLE is fatigue, and low blood levels of comple- classified as an autoimmune disease in ment are the most common. Other signs which the body seems to be unable to include pleuritis, pericarditis, myocar- maintain normal mechanisms of toler- ditis, neurological changes including be- ance to self-antigens. Activation of T havioral changes and seizure activity helper cells and B cells results in the (neural lupus), gastrointestinal ulcera- production of autoantibodies that at- tions, Raynaud’s phenomenon (present tack antigens in the cytoplasm and nu- in about 20% of patients), and other cleus of cells and on the surface of blood problems caused by inflammatory cells. The exact cause of SLE is un- changes of the blood vessels or connec- known: genetic defects, hormonal tive tissue. Most patients are prone to changes, infection, physical or mental infection. stress, some drugs, immunizations, and TREATMENT: No cure for SLE exists, environmental triggers (sunlight, UV and complete remission is rare. About light exposure) are possible predispos- 25% of patients have mild disease, dem- ing factors. SEE: autoimmune disease; onstrating only minor skin and hema- glomerulonephritis. tological signs, and can be treated with Autoantibodies can react with self-an- nonsteroidal anti-inflammatory drugs tigens to form immune complexes in for their arthritis symptoms and topical such large numbers that they cannot be treatment (sometimes with corticoste- completely excreted; the immune com- roid creams) for skin lesions. Rashes plexes may precipitate within blood ves- may respond to antimalarials (e.g., hy- sels, producing inflammation at the site droxychloroquine), but patients must be and disrupting the flow of blood and observed closely for the possibility of oxygen to tissues. These deposits are drug-induced retinal damage. Other particularly damaging in the glomeruli. treatments for skin rash include quin- Autoantibodies also promote the de- acrine, retinoids, and dapsone. Life- struction of cells by stimulating neutro- threatening and severely disabling con- phil and macrophage phagocytic activ- ditions should be treated with high ity, which increases cell destruction doses of corticosteroids and supplemen- from trauma, infection, or drugs. tal calcium to minimize osteoporosis, DIAGNOSIS: In 1997, revised criteria which may be an undesired side effect for diagnosis of SLE were established. of long-term glucocorticoid use. Immu- short The diagnosis can be made if four or nosuppressive drugs are used for severe standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

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exacerbations and to reduce steroid dos- age. PROGNOSIS: The prognosis depends on which organ systems are involved, how severely they are damaged, and how rapidly the disease progresses. Ten-year survival rates are high (80%). Renal failure and infections are the most common causes of death. PATIENT CARE: Patient education related to the disease, diagnostic pro- cedures, and treatment is essential in lupus, as in any chronic disease. Ongo- ing assessment is carried out to assess flares of the illness. The purpose, proper dosage, use, and side effects of drugs is taught. Patients need emotional sup- port to help cope with changes in ap- pearance. Patients should be taught to wear clothing and hats that block direct sunlight, use a sunscreen with a 15 or higher protection factor, and to main- tain a diet appropriate for their renal functional status. The health care pro- fessional should help establish a regi- men for adequate relief of both the mus- culoskeletal pain and chronic fatigue experienced by most patients, encour- aging adequate rest. Heat packs relieve SYSTEMIC LUPUS ERYTHEMATOSUS joint stiffness and pain, and regular Facial manifestations of systemic lupus gentle exercise helps to maintain full erythematosus. range of motion. Physical and occupa- tional therapy consultations are pro- vided as appropriate. Additional sup- ing from percussion of the external port and teaching depend on the organ branch of the sciatic nerve. system most affected by the disease. If lute, luting agent (loot) A compound the female patient of childbearing age used in dentistry to bond surfaces to- has no renal or neurologic impairment, gether and make them impermeable. Compounds identified as luting agents she can have a safe, successful preg- may be cements, resins, or glass ionom- nancy if desired. Over time, patients ers. with severe progressive disease need as- luteal (looЈte¯-a˘l) [L. luteus, yellow] Pert. sistance in coping with chronic illness to the corpus luteum, its cells, or its hor- and the possibility of mortality. Refer- mones. rals to the Lupus Foundation of Amer- luteal phase defect A deficiency in either ica (202-349-1155; www.lupus.org) and the amount or the duration of postovu- the Arthritis Foundation (800-283- latory progesterone secretion by the 7800; www.arthritis.org) are helpful. corpus luteum. Insufficient hormonal SEE: illus. stimulation results in inadequate prep- l. vulgaris Tuberculosis of the skin; aration of the endometrium for success- characterized by patches that break ful implantation and support of the down and ulcerate, leaving scars on growing embryo. This rare condition is healing. associated with infertility or habitual lupus-like syndrome A cluster of symp- spontaneous first-trimester abortion. toms resembling an autoimmune dis- SEE: menstrual cycle. ease (including arthritis, pleural or lutein (lu¯ Јte¯-ı˘n) A yellow, antioxidant pericardial effusions, and rashes) some- pigment (a “carotenoid”) derived from times seen in patients with widespread leafy green vegetables, the corpus lu- malignancy. teum, egg yolk, and fat cells or lipo- LUQ left upper quadrant of abdomen. chromes. Its consumption in the diet Luque wires (look) Wires used in the has been linked to a decreased risk of surgical stabilization of scoliosis. Trans- age-related macular degeneration. verse traction on each vertebra is ac- luteinic (looЉte¯-ı˘nЈı˘k) Concerning the cor- complished by wrapping flexible wires pus luteum of the ovary. around the affected vertebrae and at- luteinization (lu¯ Љte¯-ı˘n-ı¯-za¯Јshu˘n) The taching the wires to flexible rods. process of development of the corpus lu- Lust’s reflex (lu˘sts) [Franz Alexander teum within a ruptured graafian follicle. Lust, Ger. pediatrician, b. 1880] Dorsal Lutembacher’s syndrome (looЈte˘m- short flexion and abduction of the foot result- ba˘kЉe˘rz) [Rene´Lutembacher, Fr. phy- standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh luteolysin 1372 Lyme disease base of rh

sician, 1884–1916] Atrial septal defect carotenemia caused by eating excessive of the heart with mitral stenosis. amount of foods that contain lycopene. luteolysin (looЉte¯-o¯-lı¯Јsı˘n) [L. luteus, yel- lycoperdonosis (lı¯Љko¯-pe˘rЉdo˘n-o¯Јsı˘s) [Gr. low, ϩ Gr. lysis, dissolution] Some- lykos, wolf, ϩ perdesthai, to break thing that promotes disintegration of wind, ϩ osis, condition] A respiratory the corpus luteum. disease caused by inhaling large quan- luteoma (lu¯ Љte¯-o¯Јma˘) [L. luteus, yellow, tities of spores from the mature mush- ϩ Gr. oma, tumor] An ovarian tumor room commonly called puffball. Lyco- containing lutein cells. perdon is the genus of fungi to which luteotropin (looЉte¯-o¯-tro¯Јpı˘n) Luteiniz- most puffballs belong. ing hormone. lycopodium (lı¯-ko¯-po¯Јde¯-u˘ m) A yellow lutetium (lu¯-te¯Јshe¯-u˘ m) SYMB: Lu. A powder formed from spores of Lycopo- rare element; atomic weight 174.97; dium clavatum, a club moss. It is used atomic number 71. as a dusting powder and as a desiccant luteum (lu¯ Јte¯-u˘ m) [L.] Yellow. and absorbent. luting Cementation. lye (lı¯) [AS. leag] 1. Liquid from leach- LUTS A commonly used abbreviation for ing of wood ashes. 2. Any strong alka- “lower urinary tract symptoms,” that is, line solution, esp. sodium or potassium for symptoms such as difficulty initiat- hydroxide. SEE: alkali; potassium hy- ing or maintaining a strong and com- droxide; sodium hydroxide. fortable urinary stream. Lyell disease (lı¯Јe˘lz) Toxic epidermal ne- Lutzomyia A genus of bloodsucking sand- crolysis. flies. They are vectors of leishmaniasis lying-in 1. Historical term for the puer- and Oroyo fever. peral state. 2. Being hospitalized for the Lutz-Splendore-Almeida disease (lu˘ts) purpose of childbearing. [A. Lutz, Brazilian physician, 1855– Lyme disease (lı¯m) [Lyme, CT, where a 1940; A. Splendore, contemp. Italian cluster of cases was reported in 1975] physician; Floriano P. de Almeida, Bra- ABBR: LD. A multisystem disorder zilian physician, b. 1898] South Amer- caused by the spirochete Borrelia burg- ican blastomycosis. dorferi and the most common tick-borne lux (lu˘ks) [L., light] A unit of light in- disease in the U.S. The disease is en- tensity equivalent to 1 lumen/m2. demic in New England, but cases have luxatio erecta (lu¯ks-a˘Јse¯-o¯e¯-re˘kЈtah) been reported in all 50 states and in 20 Subglenoid displacement of the head of other countries, including Germany, the humerus associated with disruption Switzerland, France, and Australia. It of the rotator cuff. occurs most often in the spring and sum- luxation (lu˘ks-a¯Јshu˘n) [L. luxatio, dislo- mer, when its deer tick vectors (of the cation] 1. Displacement of organs or ar- genus Ixodes) are most active. Prompt removal of visible ticks from the skin be- ticular surfaces; complete dislocation of fore they become attached or gain access a joint. SEE: subluxation. 2. In den- to the bloodstream (i.e., in the first 24 to tistry, injury to supporting tissues that 48 hr) decreases the risk of transmis- results in the loosening of the teeth with sion. SEE: Nursing Diagnoses Appen- rotation or partial displacement. dix. Luxol fast blue (lu˘ksЈo˘lЉ) An alcohol-sol- ETIOLOGY: The infected tick injects uble sulfonated copper phthalcyanine its spirochete-laden saliva into the stain, used primarily in neuropathol- bloodstream, where they incubate for 3 ogy. It is taken up by phospholipids and to 32 days and then migrate to the skin, choline and stains myelin blue. causing the characteristic erythema mi- LV left ventricle. grans (EM) rash. LVEDP left ventricular end-diastolic pres- DIAGNOSIS: The disease is best di- sure. Ј agnosed by the presence of EM, which lyase (lı¯ a¯s) The class name for enzymes begins as a red macule or papule at the (such as decarboxylase, aldolase, and site of the tick bite and expands in a red synthases) that remove organic bonds ring, leaving a clear center like a target between carbon atoms, carbon and oxy- or bull’s eye. The lesion usually feels hot gen atoms, or carbon and nitrogen at- and itchy and may grow to over 20 in oms without hydrolysis or oxygenation. (50.8 cm) as more lesions erupt. The le- One of the molecules that is created has sion is later replaced by red blotches or a double bond. diffuse urticaria. Conjunctivitis, mal- lycanthropy (lı¯-ka˘nЈthro¯-pe¯) [Gr. lykos, aise, fatigue, and flulike symptoms and wolf, ϩ anthropos, man] A mania in lymphadenopathy may occur. Antibody which one believes oneself to be a wild tests for Borrelia burgdorferi with an beast, esp. a wolf. enzyme-linked immunosorbent assay lycopene (lı¯Јko¯-pe¯n) An antioxidant red (ELISA) test are also used for diagnosis carotenoid pigment found in tomatoes in patients with a history of exposure and other red fruits and berries. and signs and symptoms of Lyme dis- lycopenemia (lı¯Љko¯-pe˘-ne¯Јme¯-a˘) [lyco- ease but with no evidence of rash. The short pene ϩ Gr. haima, blood] A type of antibodies are developed against flagel- standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh Lyme disease 1373 Lyme disease base of rh

lar and outer surface proteins on the places where ticks may be located, peo- spirochete. SEE: illus. ple should wear clothing impregnated with insect repellents, hats, long sleeves, pants tucked into socks, heavy shoes, and a tick repellent containing DEET (N,N-diethyltoluamide). Tick re- pellent should not be directly applied to an infant or toddler’s skin because of the danger of neurotoxicity. If possible, peo- ple should stay on paths and away from high grass or brush. They should check clothing carefully for ticks when leaving those areas although tick nymphs, which are smaller than 1 mm in length, may not be easily seen. Once home, peo- ple should remove and wash clothing and check their entire body, esp. the hairline and ankles, for ticks or nymphs. If a tick or nymph is found, it should be carefully removed with tweez- ers, esp. the head and mouth parts, but the body of the tick or nymph must not be squeezed. The site may then be LYME DISEASE cleansed with an antiseptic, but should be observed for signs of infection (red- Classic rash with central clearing ness, swelling, pain, rash), and the pri- mary health care provider contacted if SYMPTOMS: The course of Lyme dis- ease is divided into three stages. infection is suspected. Some people 1 localized infection: begins with the make the mistake of trying to remove tick bite and proceeds as above. ticks or nymphs with alcohol, a lighted 2 disseminated infection: begins match, or petroleum jelly. These mea- weeks to months later. The spirochetes sures are ineffective and may increase spread to the rest of the body through the risk of transmission of tick-borne the blood, in some cases causing arthri- diseases. Prophylactic antibiotics gen- tis (esp. of the knee joints), muscle pain, erally should not be requested (or cardiac dysrhythmias, pericarditis, lym- given). Although pet dogs may receive phadenopathy, or meningoencephalitis. Lyme vaccine, they should still be Nonprotective antibodies develop dur- checked to prevent them from bringing ing this stage. ticks into the house. 3 chronic infection: begins weeks to PATIENT CARE: The patient is years after the initial bite. Patients de- checked for any drug allergies. Pre- velop mild to severe arthritis, encepha- scribed pharmacologic therapy is ex- litis, or both, which rarely are fatal. plained to the patient, including dosing TREATMENT: Oral doxycycline or schedule, the importance of completing ampicillin (14–21 or –28 day course) ef- the course of therapy even if he feels fectively eradicates early uncomplicated better, and adverse effects. Patients be- Lyme disease. Erythromycin or cefurox- ing treated for Lyme disease often re- ime axetil may be administered to pa- quire antibiotics for a prolonged period, tients allergic to penicillin. Patients esp. in advanced stages, which in- with cardiac and neurological involve- creases their risk for developing adverse ment may need to be treated with intra- effects (e.g., diarrhea). Methods for venous cephalosporins. dealing with these problems are ex- PROGNOSIS: When the disease is plained. Patients with chronic Lyme treated early, results are good. If disease often require assistance to deal treated late, convalescence is prolonged, with changes in lifestyle, family inter- but complete recovery is the usual out- actions, and ability to perform daily activ- come in most patients. ities. Available local and national support PREVENTION: The Centers for Dis- groups can assist with such problems. Pa- ease Control recommends that people tients should be made aware that one oc- should discuss with their health care currence of Lyme disease does not prevent providers the possibility of getting a recurrences. The U.S. Department of Lyme disease vaccination if they are be- Health and Human Services has made tween 15 and 70 years old; live, work, or Lyme disease prevention a priority under vacation in endemic areas; or frequently its program “Healthy People 2010.” go into wooded or grassy areas. The vac- Patients can be referred to the Lyme Dis- cine is not recommended for children, ease Foundation (860-870-0070; http:// pregnant women, and those who do not www.lyme.org) or the American Lyme live in or visit endemic areas. Disease Foundation (http://www.aldf.com) short When planning to spend time in for information and support. standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh lymph 1374 lymphadenitis base of rh lymph (lı˘mf) [L. lympha] The name memory cells, and macrophages, before given to tissue fluid that has entered exiting through the efferent vessel. An- lymph capillaries and is found in larger tibodies produced in the node travel via lymph vessels. It is alkaline, clear, and the lymph to the blood for distribution colorless, although lymph from the throughout the body. small intestine appears milky from the An increase in the size of the node absorbed fats (chyle). The protein con- (lymphadenopathy) indicates a high tent of lymph is lower than that of level of activity (e.g., while combating plasma, osmotic pressure is slightly infection or cancer or when participat- higher, and viscosity slightly less. Spe- ing in local inflammatory reactions). cific gravity is 1.016 to 1.023. Lymph nodes occur singly or in Lymph is mostly water, and contains closely connected chains, which receive albumin, globulins, salts, urea, neutral lymph from a single organ or region of fats, and glucose. Its cells are mainly the body. Prominent chains in the neck, lymphocytes and monocytes, formed in axilla, groin, and mesentery remove for- the lymph nodes and nodules. eign antigens from the lymph coming Lymph capillaries, found in most tis- from the head, arms, legs, and the gas- sue spaces, collect tissue fluid, which is trointestinal tract, respectively. then called lymph. Lymph from the lymph-, lympho- Combining forms lower body flows to the cisterna chyli in meaning lymph. the abdomen and continues upward lymphadenectasis (lı˘m-fa˘dЉe˘-ne˘kЈta˘-sı˘s) through the thoracic duct, which re- [L. lympha, lymph, ϩ Gr. aden, gland, ceives intercostal lymph vessels, the left ϩ ektasis, dilatation] Dilatation or dis- subclavian trunk from the left arm, and tention of a lymph node. the left jugular trunk from the left side lymphadenectomy (lı˘m-fa˘dЉe˘-ne˘kЈto¯-me¯) of the head. The thoracic duct empties [ЉϩЉϩektome, excision] Surgical lymph into the blood in the left subcla- removal of a lymph node, as in a biopsy. vian vein near its junction with the left lymphadenitis (lı˘m-fa˘dЉe˘n-ı¯Јtı˘s) [ЉϩЉ jugular vein. The right lymphatic duct ϩ itis, inflammation] Inflammation of drains lymph from the upper right lymph nodes, caused by the activation quadrant of the body and empties into of phagocytes and lymphocytes, which the right subclavian vein. SEE: lym- encounter large numbers of microorga- phatic system for illus. nisms, cancer cells, or other antigenic As lymph flows through the lymph material. Local swelling and pain are vessels toward the subclavian veins, it common symptoms and often help cli- passes through lymph nodes, which con- nicians diagnose regional diseases (e.g., tain macrophages to phagocytize bacte- the anterior cervical lymph nodes be- ria or other pathogens that may be come tender and enlarged in people present. with strep throat; the inguinal lymph l. channel Lymph sinus. nodes enlarge and hurt in some sexually inflammatory l. An exudate due to transmitted diseases). inflammation. Lymph node inflammation sometimes l. node One of thousands of small is associated with inflammation of the kidney-shaped organs of lymphoid tis- lymphatic vessels (lymphangitis) lead- sue that lie at intervals along the lym- ing into the node. Lymphatic inflam- phatic vessels. SYN: lymph gland. SEE: mation subsides when the underlying illus.; immune response; inflammation; infection is treated. Lymphadenitis of lymph; lymphocyte. unknown cause may require lymph ANATOMY AND PHYSIOLOGY: It con- node biopsy (e.g., excisional or needle bi- tains large numbers of lymphocytes and opsies) or aspiration. SEE: inflamma- macrophages connected by a network of tion; lymphangitis. reticular fibers and grouped into folli- SYMPTOMS: The disease is charac- cles. Lymph enters a node through the terized by a marked increase of tissue, afferent vessels along the larger outer with possible suppuration. Swelling, rim and passes through the subcapsular pain, and tenderness are present. The sinus lined with macrophages and into disease usually accompanies lymphan- the follicles of the cortex. Follicles con- gitis. tain leukocytes that respond to foreign ETIOLOGY: The condition is caused antigens present in the lymph. by drainage of bacteria or toxic sub- As lymph flows through channels be- stances into the lymph nodes. The eti- tween and within the follicles, macro- ology may be specific, as when caused by phages destroy microorganisms and the organisms of typhoid, syphilis, or tu- abnormal cells by direct lysis or phago- berculosis, or nonspecific, in which the cytosis, activated T lymphocytes multi- causative organism is not identified. ply, and B lymphocytes proliferate and TREATMENT: Hot, moist dressings manufacture antigen-specific antibod- should be applied. Incision and drain- ies. Lymph then passes through the age are necessary if abscesses occur. An- paracortex and the medulla of the node, tibiotics should be given as indicated. short which contain mature T and B cells, B tuberculous l. Lymph node inflam- standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh lymphadenocele 1375 lymphadenopathy base of rh

AFFERENT LYMPHATIC VESSEL

CAPSULE

CORTEX

NODAL VEIN NODAL ARTERY HILUM VALVE

A EFFERENT LYMPHATIC VESSEL

BACTERIA

LYMPHOCYTES

B

NEUTROPHIL

ANTIBODY MOLECULE PLASMA CELL (ENLARGED) MACROPHAGE ANTIGEN (ENLARGED) LYMPH NODE (A) section through a lymph node, (B) microscopic detail of destruction of bacteria

mation caused by Mycobacterium tuber- ϩ eidos, form, shape] Resembling a culosis (MTB), with granuloma forma- lymph node or lymph tissue. tion and caseating necrosis within the lymphadenopathy (lı˘m-fa˘dЉe˘-no˘pЈa˘-the¯) node. The most common presentation is [ЉϩЉϩpathos, disease] Enlarge- the finding of a neck mass in a febrile ment of lymph nodes (LN), typically to patient (a condition called “scrofula”), greater than 1.5 cm. The increased size although MTB and other mycobacteria is caused by activation and proliferation also can invade lymph nodes in other of lymphocytes and phagocytic white parts of the body. SEE: tuberculosis. blood cells within the node or by inva- lymphadenocele (lı˘m-fa˘dЈe˘-no¯-se¯lЉ)[Љϩ sion of the node by tumor. Most often, Љϩkele, tumor, swelling] A cyst of a lymphadenopathy is found in nodes in- lymph node. volved in local, regional, or systemic in- lymphadenogram (lı˘m-fa˘dЈe˘-no¯-gra˘mЉ) fections; it results occasionally from [ЉϩЉϩgramma, something written] cancers. Lymphadenopathy may also be A radiograph of a lymph gland. found in an array of other, less common lymphadenography (lı˘m-fa˘dЉe˘-no˘gЈra˘-fe¯) illnesses, including thyroiditis, thyro- [ЉϩЉϩgraphein, to write] Radi- toxicosis, autoimmune diseases (e.g., ography of the lymph glands after injec- rheumatoid arthritis), sarcoidosis, and tion of radiopaque material. drug reactions (e.g., phenytoin). SEE: il- short lymphadenoid (lı˘m-fa˘dЈe˘-noyd) [ЉϩЉ lus. standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh lymphadenopathy 1376 lymphatic base of rh

L. fiber, fiber, ϩ Gr. oma, tumor] Fi- broma and lymphangioma combined. lymphangiography (lı˘m-fa˘nЉje¯-o˘gЈra˘-fe¯) [ЉϩЉϩgraphein, to write] Imme- diate radiological investigation of the lymphatic vessels after injection of a contrast medium via cutdown, usually on the dorsum of the hand or foot. De- layed films are taken to visualize the nodes. This technique has been replaced by computed tomography and magnetic resonance imaging. SYN: lymphogra- phy. lymphangiology (lı˘m-fa˘nЉje¯-o˘lЈo¯-je¯) [Љϩ CERVICAL LYMPHADENOPATHY Љϩlogos, word, reason] The branch of medical science concerned with the Squamous cell carcinoma of the neck lymphatic system. lymphangioma (lı˘m-fa˘nЉje¯-o¯Јma˘) [ЉϩЉ Enlarged LNs may be tender or not; ϩ oma, tumor] A tumor composed of tenderness often is present when lymph lymphatic vessels. nodes swell rapidly (e.g., in response to cavernous l. Dilated lymph vessels infections, hypersensitivity reactions, or filled with lymph. some fulminant lymphomas). Rock- cystic l. Multilocular cysts filled with hard, enlarged, and immobile LNs are lymph. The condition is usually congen- typical of metastatic cancer, whereas ital. rubbery LNs are found in lymphomas. lymphangiophlebitis (lı˘m-fa˘nЉje¯-o¯-fle˘- LNs that do not resolve spontaneously bı¯Јtı˘s) [ЉϩЉϩphleps, vein, ϩ itis, within 4 to 6 weeks, or for which no ob- inflammation] Inflammation of the vious explanation exists, usually are lymphatic vessels and veins. sampled by biopsy or aspiration. lymphangioplasty (lı˘m-fa˘nЈje¯-o¯-pla˘sЉte¯) dermatopathic l. Widespread lym- [ЉϩGr. angeion, vessel, ϩ plassein, phadenopathy secondary to various to form] The formation of artificial lym- skin disorders. phatics or the use of microsurgical tech- lymphadenosis benigna cutis (lı˘m-fa˘dЉe˘- Ј Ј Ј nique to reestablish lymphatic or no¯ sı˘s be¯-nı¯ na˘cu¯ tı˘s) A benign collec- lymphogenous continuity. SYN: lym- tion of lymphocytes in the skin. phoplasty. lymphadenotomy (lı˘m-fa˘dЉe˘-no˘tЈo¯-me¯) Љ ЉϩЉϩ lymphangiosarcoma (lı˘m-fa˘n je¯-o¯-sa˘r- [ tome, incision] Surgical in- ko¯Јma˘) [ЉϩЉϩsarx, flesh, ϩ oma, cision of a lymph node. tumor] A malignant neoplasm that de- lymphadenovarix (lı˘m-fa˘dЉe˘-no¯-va¯Јrı˘ks) velops from the endothelial lining of [ЉϩЉϩL. varix, a twisted vein] En- lymphatics. largement of lymph nodes due to in- lymphangiotomy (lı˘m-fa˘nЉje¯-o˘tЈo¯-me¯) [Љ creased pressure in the lymph vessels. ϩЉϩtome, incision] Incision into a lymphangial (lı˘m-fa˘nЈje¯-a˘l) [ЉϩGr. angeion, vessel] Concerning lymph ves- lymphatic vessel. lymphangitis (lı˘mЉfa˘n-jı¯Јtı˘s) [ЉϩGr. sels. ϩ lymphangiectasis (lı˘m-fa˘nЉje¯-e˘kЈta˘-sı˘s) angeion, vessel, itis, inflammation] [ЉϩЉϩektasis, dilatation] Benign Inflammation of the lymphatic vessels swelling in all or part of an extremity, draining a body part that is inflamed or as the result of dilation of the subcuta- infected. Red streaks are present along neous and deep lymphatic vessels. It oc- the inflamed vessels and are accompa- curs mostly in children and may be se- nied by heat, pain, and swelling; lymph vere enough to cause deformity. nodes in the area are enlarged and ten- Acquired lymphangiectasis can occur as der. Treatment consists of antibiotics a complication of surgery or radiation specific to the organism causing the in- therapy for cancer. SYN: lymphectasia. fection, most commonly group A beta- lymphangiectomy (lı˘m-fa˘nЉje¯-e˘kЈto¯-me¯) hemolytic streptococci (occasionally [ЉϩЉϩektome, excision] Surgical staphylococci). If the infection is not removal of lymph vessels. contained it can produce septicemia. lymphangiitis (lı˘m-fa˘nЉje¯-ı¯Јtı˘s) [ЉϩЉ SYMPTOMS: The condition is char- ϩ itis, inflammation] Inflammation of acterized by the onset of chills and high lymph vessels. SYN: angiolymphitis. fever, with moderate swelling and pain. lymphangioendothelioma (lı˘m-fa˘nЉje¯-o¯- PATIENT CARE: Elevating the af- e˘nЉdo¯-the¯-le¯-o¯Јma˘) [ЉϩЉϩendon, fected part of the body so that local lym- within, ϩ thele, nipple, ϩ oma, tu- phatics can drain reduces pain and mor] Endothelioma originating from helps the underlying infection to re- lymph vessels. solve. Antibiotics, and often, antipyretic lymphangiofibroma (lı˘m-fa˘nЉje¯-o¯-fı¯- and analgesic drugs are administered. short bro¯Јma˘) [ЉϩGr. angeion, vessel, ϩ lymphatic (lı˘m-fa˘tЈı˘k) [L. lymphaticus] standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh lymphatic 1377 lymphedema base of rh

Pert. to lymph and to the system of en- carrying lymph away from a lymph dothelial vessels that carry it. node. ANATOMY: A lymph vessel carries lymphaticostomy (lı˘m-fa˘tЉı˘-ko˘sЈto¯-me¯) lymph toward a subclavian vein. [L. lymphaticus, lymphatic, ϩ Gr. Plasma that leaves blood capillaries and stoma, mouth] The making of a per- becomes tissue fluid is collected by manent aperture into a lymphatic duct, lymph capillaries. The larger lymph e.g., thoracic duct shunt. vessels resemble veins in that they have lymphatic system The system that in- valves to prevent backflow of lymph. cludes all the lymph vessels that collect These larger vessels unite to form either tissue fluid and return it to the blood the thoracic duct or the right lymphatic (lymph capillaries, lacteals, larger ves- duct, which empty lymph into the blood sels, the thoracic duct, and the right in the left and right subclavian veins, lymphatic duct), the lymph nodes and respectively. The lymph capillaries nodules, the spleen, and the thymus. within the villi of the small intestine SEE: illus.; lymph. (lacteals) absorb the fat-soluble end lymphatitis (lı˘mЉfa˘-tı¯Јtı˘s) [ЉϩGr. itis, products of digestion, which are trans- inflammation] An inflammation of the ported in the form of chylomicrons to the lymphatic system. blood by the larger lymphatic vessels. lymphatolysis (lı˘mЉfa˘-to˘lЈı˘-sı˘s) [ЉϩGr. SEE: lymphatic system. lysis, dissolution] Destruction of lym- afferent l. Any of the small vessels phatic vessels or tissue. carrying lymph toward a lymph node. lymphatolytic (lı˘mЉfa˘-to¯-lı˘tЈı˘k) Destruc- l. capillary One of the smallest lym- tive to lymphatics. phatic vessels. These thin-walled tubes lymphectasia (lı˘mfЉe˘k-ta¯Јze¯-a˘) [L. lym- consist of a single layer of endothelium pha, lymph, ϩ Gr. ektasis, dilatation] ending blindly in a swollen or rounded Lymphangiectasis. end, and form a dense network in most lymphedema (lı˘mf-e˘-de¯Јma˘) [ЉϩGr. tissues of the body. They are generally oidema, swelling] An abnormal accu- slightly larger in diameter than blood mulation of tissue fluid (potential capillaries. Because they collect inter- lymph) in the interstitial spaces. The stitial fluid, the composition of the mechanism for this is either impair- lymph varies according to the tissue be- ment of normal uptake of tissue fluid by ing drained. Intestinal lymphatics con- the lymphatic vessels or the excessive tain fatty materials during digestion; production of tissue fluid caused by ve- those from the liver contain proteins. nous obstruction that increases capil- SEE: illus. lary blood pressure. Stagnant flow of tis- efferent l. Any of the small vessels sue fluid through body structures may

TISSUE FLUID

CELLS LYMPH CAPILLARY

ARTERIOLE

VENULE

BLOOD CAPILLARY

LYMPHATIC CAPILLARIES short Arrows indicate movement of plasma, lymph, and tissue fluid standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh lymphedema 1378 lymphedema base of rh

CERVICAL NODES RIGHT LYMPHATIC DUCT

LEFT SUBCLAVIAN VEIN RIGHT SUBCLAVIAN VEIN

AXILLARY NODES

THORACIC DUCT SPLEEN CISTERNA CHYLI

INGUINAL NODES

THE LYMPHATIC SYSTEM

make them prone to infections that are Common causes of lymphedema in- difficult to treat; as a result lymphede- clude neoplastic obstruction of lym- matous limbs should be protected from phatic flow (e.g., in the axilla, in meta- cuts, scratches, burns, and blood draw- static breast cancer); postoperative short ing. interference with lymphatic flow (e.g., standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh lymphedema 1379 lymph node basin base of rh

after axillary dissection); infectious a professional, as an improperly fitted blockade of lymphatics (e.g., in filaria- device may irritate skin and other tis- sis); radiation damage to lymphatics sues, resulting in additional swelling. (e.g., after treatment of pelvic, breast, Sensible weight reduction programs or lung cancers). All of these are second- based on mild caloric restriction and ary (acquired) lymphedemas. Rarely, gentle exercise help to alleviate symp- lymphedema also may occur congeni- toms. Overexertion of affected limbs tally (Milroy’s disease), or develop at the should be avoided. Using the affected onset of puberty or during adulthood limb for activities of daily living (bath- from an unknown cause that may be re- ing, hair-brushing) helps to drain lymph lated to vascular anomalies (primary fluid. Supporting the arm on the back of lymphedema). In the U.S. and other de- a chair or couch provides helpful eleva- veloped countries, the leading cause of tion for lymph drainage. In acute care secondary lymphedema is surgical or settings, the affected limb should be radiation therapy for cancer, esp. if ac- identified by the patient and by health companied by lymph node dissection. care providers using a loose-fitting, col- SEE: blockade, lymphatic; elephantia- ored (bright pink) armband to ensure sis; pump, lymphedema. that blood drawings, injections, and Lymphedema occurs in four stages (0 blood pressure readings are not done on to 3): that limb. Skin should be kept clean and 0. Subclinical stage in which lymph moisturized to limit chapping or chafing transport is known to be impaired but leading to breakdown. The patient is no signs or symptoms are obvious (may taught to avoid cuts and abrasions, as last for years); when using kitchen knives or other im- 1. Tissue is soft with pitting edema; plements, to wear gloves when garden- swelling decreases with elevation; ing and to wash and inspect skin after 2. Tissue is swollen, but firmer and such activities, and to clean any skin thus may not show pitting; edema does breaks that occur, treating them with not resolve completely with elevation; an antibacterial cream or ointment and and a sterile dry dressing. In cases of lower 3. The affected limb is grossly en- extremity edema, sitting with the legs larged and misshapen; skin breakdown in a dependent position, crossing the and infection often occur. legs, or standing for prolonged periods SYMPTOMS: Symptoms of lymph- should be avoided. Extremes of heat and edema may include a feeling of heavi- cold exposure should be avoided. The ness, tiredness, aching, weakness, and health care provider should be notified fullness in a limb impairing flexibility or if the limb develops a rash or itching or interfering with the wearing of jewelry, pain or if the patient develops fever or watches, or clothing. flu-like symptoms. Local support groups TREATMENT: Treatment goals in- can assist patients in dealing with body clude maintaining use of the affected image issues, and fitting clothing to limb and preventing complications. asymmetrical limbs. Resources for fur- PATIENT CARE: A combination of ther information on lymphedema man- manual lymphatic drainage, compres- agement include The National Lymph- sion devices, and protection of the af- edema Network and other support fected limb can make a positive differ- organizations such as the American ence in a patient’s quality of life. Patient Cancer Society. management by physiatrists, other phy- congenital l. Chronic pitting edema sicians experienced in lymphedema of the lower extremities. SYN: Milroy’s care, certified nurses, and therapists is disease. crucial. Careful measurement of the af- lymphedema praecox Obstruction of the fected limb with comparison to its op- lymphatic channels, producing edema, posite and diagnostic testing help to which occurs primarily in women be- rule out other causes. If necessary, lym- tween the ages of 10 and 25; its cause is phangioscintigraphy can be used to ex- unknown. The interstitial fluid that ac- amine the anatomy and functioning of cumulates first appears in the feet but the lymph system. Patients and their can travel proximally to the trunk; it partners can be taught effective tech- continues to accumulate throughout niques to use at home. Compression de- life. When the edema becomes severe, it vices are fitted over the affected limb to predisposes the patient to chronic ulcers help maintain or reduce swelling. Com- and superimposed infections of the legs. pression pumps use air or fluid pressure lymph node basin The collected lymph to mimic massage’s beneficial effects. nodes into which lymph channels drain They are designed to move lymphatic from a particular region of the body. Le- fluid back toward functional nodes by sions on an arm, for example, drain into providing sequential, even pressure the axillary basin, while those on a leg from the distal to the proximal portions drain into the groin. Similarly, prostate of the affected limb. Compression cancers drain into pelvic and periaortic short sleeves or stockings should be fitted by basins. standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh lymphoblast 1380 lymphocytosis base of rh lymphoblast (lı˘mЈfo¯-bla˘st) [ЉϩGr. autoreactive l. Lymphocytes that re- blastos, germ] An immature cell that act with “self”-antigens. Most of these gives rise to a lymphocyte. SYN: lym- cells are eliminated during lymphocyte phocytoblast. lymphoblastic, adj. maturation or by activation-induced cell lymphoblastoma (lı˘mЉfo¯-bla˘st-o¯Јma˘) [Љ death. SYN: self-reactive lymphocyte. ϩЉϩoma, tumor] Lymphosarcoma. Bl. A lymphocyte formed from plu- lymphoblastomatosis (lı˘mЉfo¯-bla˘sЉto¯- ripotent stem cells in the bone marrow ma˘-to¯Јsı˘s) [ЉϩЉϩoma, tumor, ϩ that migrates to the spleen, lymph osis, condition] A condition produced by nodes, and other peripheral lymphoid lymphoblastomas. tissue where it comes in contact with lymphoblastosis (lı˘mЉfo¯-bla˘s-to¯Јsı˘s) [Љ foreign antigens and becomes a mature ϩЉϩosis, condition] An excessive functioning cell. Mature B cells are able number of lymphoblasts in the blood. to independently identify foreign anti- lymphocele (lı˘mЈfo¯-se¯l) [L. lympha, gens and differentiate into antibody- lymph, ϩ Gr. kele, tumor, swelling] A producing plasma cells or memory cells; cyst that contains lymph. their activity also may be stimulated by lymphocytapheresis (lı˘mЉfo¯-sı¯-ta˘-fa˘- IL-2 (previously called B-cell growth re¯Јsı˘s) [ЉϩGr. aphairesis, removal] factor). Plasma cells are the only source Removal of lymphocytes from the blood of immunoglobulins (antibodies). Mem- after it has been withdrawn. The blood ory cells enable the body to produce an- is then returned to the donor. tibodies quickly when it is invaded by lymphocyte (lı˘mЈfo¯-sı¯t) [L. lympha, the same organism at a later date. SYN: lymph, ϩ Gr. kytos, cell] A white B cell. SEE: humoral immunity; im- blood cell responsible for much of the mune response. body’s immune protection. Fewer than self-reactive l. Autoreactive lympho- 1% are present in the circulating blood; cyte. the rest lie in the lymph nodes, spleen, Tl. T cell. and other lymphoid organs, where they tumor-infiltrating l. Lymphocytes can maximize contact with foreign an- found in solid tumors (e.g., lung cancers, tigens. SEE: illus.; B cell; T cell; blood melanomas, and renal cell carcinomas). for illus.; cell, natural killer; cell, Tumor-infiltrating lymphocytes include plasma; immunity, cell-mediated; im- helper T cells and cytotoxic T cells; they munity, humoral. participate in tumor recognition and, in some cases, tumor destruction. lymphocyte immune therapy ABBR: LIT. A purported treatment for recur- rent miscarriage, in which cells from a potential father are infused into a woman who has had previous loss of pregnancy after intercourse with this partner.

LIT has not been shown to prevent spontaneous abortion and may be hazardous to the recipient of the infused cells. In the U.S., the Food and Drug Ad- NORMAL LYMPHOCYTES ministration (FDA) permits research on LIT but not its use in everyday medical (Orig. mag. ϫ1000) practice. Lymphocytes vary from 5 to 12 ␮min diameter; subpopulations can be iden- lymphocytic colitis (lı˘mЉfa˘-sı˘tЈı˘k) ABBR: tified by unique protein groups on the LC. Chronic watery diarrhea of un- cell surface called clusters of differenti- known cause, in which the endoscopic ation. T cells, derived from the thymus, and radiological appearance of the make up approx. 75% of all lympho- bowel wall is normal. Biopsies of the cytes; B cells, derived from the bone bowel wall reveal excessive numbers of marrow, 10%. A third classification is lymphocytes within the intestinal epi- natural killer cells. In the blood, 20% to thelium. LC is equally common in men 40% of the white cells are lymphocytes. and women. It is usually diagnosed in activated l. A lymphocyte that has people aged 40 to 60. been stimulated by exposure to a spe- lymphocytoblast (lı˘mЉfo¯-sı¯Јto¯-bla˘stЉ)[Љ cific antigen or by macrophage process- ϩЉϩblastos, germ] Lymphoblast. ing so that it is capable of responding to lymphocytopenia (lı˘mЉfo¯-sı¯tЉo¯-pe¯Јne¯-a˘) a foreign antigen by neutralizing or [ЉϩЉϩpenia, lack] Lymphopenia. eliminating it. lymphocytopoiesis (lı˘mЉfo¯-sı¯tЉo¯-poy- l. activation The use of an antigen (or e¯Јsı˘s) [ЉϩЉϩpoiesis, production] mitogen in vitro) to stimulate lympho- Lymphocyte production. short cyte metabolic activity. lymphocytosis (lı˘mЉfo¯-sı¯-to¯Јsı˘s) [ЉϩЉ standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh lymphoepithelioma 1381 lymphoma base of rh

ϩ osis, condition] An excess of lymph anti-Chlamydia antibodies. Women, cells in the blood. rather than men, are targeted for lymphoepithelioma (lı˘mЉfo¯-e˘pЉı˘-the¯-le¯- screening because of their increased use o¯Јma˘) [ЉϩGr. epi, at, ϩ thele, nip- of health care and the risk of developing ple, ϩ oma, tumor] A poorly differ- PID associated with this disease. entiated squamous cell carcinoma, TREATMENT: The disease can be usually found in the nasopharynx. The treated effectively with a 3-week course tumor is infiltrated by massive numbers of doxycycline; erythromycin is used in of lymphocytes. pregnant women. Recurrent infection is lymphogenesis (lı˘mЉfo¯-je˘nЈe˘-sı˘s) [Љϩ common if barrier contraception is not Gr. genesis, generation, birth] Produc- used during intercourse. tion of lymph. lymphography (lı˘m-fo˘gЈra˘-fe¯) [L. lym- lymphogenous (lı˘m-fo˘jЈe˘n-u˘s) [ЉϩGr. pha, lymph, ϩ Gr. graphein, to write] gennan, to produce] 1. Forming lymph. Lymphangiography. 2. Derived from lymph. lymphoid (lı˘mЈfoyd) [ЉϩGr. eidos, lymphogranuloma inguinale (lı˘mЉfo¯- form, shape] 1. Consisting of lympho- gra˘nЉu¯-lo¯Јma˘) Lymphogranuloma ve- cytes. 2. Resembling lymphatic tissue. nereum. l. cell A term formerly used to des- lymphogranulomatosis (lı˘mЉfo¯-gra˘n-u¯- ignate a lymphocyte. lo¯Љma˘-to¯Јsı˘s) [Љϩgranulum, granule, lymphoidectomy (lı˘mЉfoyd-e˘kЈto¯-me¯) [Љ ϩ Gr. oma, tumor, ϩ osis, condition] ϩЉϩektome, excision] Surgical re- 1. Infectious granuloma of the lymphat- moval of lymphoid tissue. ics. 2. Hodgkin’s disease. lymphokine (lı˘mЈfo¯-kı¯n) A cytokine re- Љ lymphogranuloma venereum (lı˘m fo¯- leased by lymphocytes, including many Љ Ј ЉϩЉϩ gra˘n u¯-lo¯ ma˘) [ Gr. oma, tu- of the interleukins, gamma interferon, mor] ABBR: LGV. A sexually trans- tumor necrosis factor beta, and chemo- mitted disease, affecting about 300 kines. SEE: cytokine. patients per year in the U.S., caused by lymphokinesis (lı˘mЉfo¯-kı¯-ne¯Јsı˘s) [Љϩ Chlamydia species. It has an incubation Gr. kinesis, motion] 1. Circulation of period of about 3 to 30 days. Its hall- lymph in the lymphatic system. marks are a painless, red erosion on the 2. Movement of lymph in the semicir- genitals or rectum, followed 1 to 2 weeks cular canals of the inner ear. later by inguinal lymph node enlarge- lymphology (lı˘m-fo˘lЈo¯-je¯) [ЉϩGr. lo- ment (historically called “buboes”). gos, word, reason] The science of the These may cause fistulous tracts or ob- lymphatics. struct lymphatic channels if the infec- lymphoma (lı˘m-fo¯Јma˘) A malignant ne- tion is left untreated. Perirectal lymph oplasm originating from lymphocytes. nodes may scar and produce late rectal Common forms of lymphoma are listed obstruction. Tetracyclines cure the dis- in the subentries, below. These include ease in its initial stages but do not re- Hodgkin’s disease, mycosis fungoides, solve complications brought on by scar- non-Hodgkin’s lymphoma. SEE: Hodg- ring or lymphatic obstruction. SYN: kin’s disease. lymphogranuloma inguinale; lympho- STAGING: Staging of both Hodgkin’s pathia venereum. SEE: pelvic inflam- and non-Hodgkin’s lymphoma is as fol- matory disease; sexually transmitted disease. lows: Stage I: involvement of a single lymph node or localized involvement. SYMPTOMS: Because up to 75% of women and 50% of men have no symp- Stage II: Involvement of two or more toms, patients do not know they have lymph node regions on the same side of the disease, continue to spread it, and the diaphragm. Stage III: Involvement develop more severe infection. Sympto- of several lymph node regions on both matic patients may develop ulcerating sides of the diaphragm. Stage IV: In- vesicles on the genitals, urethral in- volvement of extra lymphatic tissue, flammation, abdominal pain, and swol- such as the bone marrow. len lymph nodes in the groin and rec- Burkitt’s l. SEE: Burkitt’s lymphoma. tum; men often have swollen testicles. cutaneous T cell l. ABBR: CTCL. A Approx 40% of women develop pelvic in- malignant non-Hodgkin’s lymphoma, flammatory disease (PID), leading to with a predilection for infiltrating the chronic pain, infertility, and an in- skin. In its earliest stages, it often is creased risk of having a tubal preg- mistaken for a mild, chronic dermatitis nancy. because it appears as itchy macules and The Centers for Disease Control rec- patches, often on the chest or trunk. ommend that all sexually active women Later, the lesions may thicken, become under 20 years of age should be nodular, or spread throughout the en- screened yearly for Chlamydia; sexually tire surface of the skin, the internal or- active women over age 20 with multiple gans, or the bloodstream. sex partners who do not use condoms follicular l. A B-cell, non-Hodgkin’s also should be screened yearly. The in- lymphoma found in adult and elderly short fection is diagnosed using fluorescent patients. It results from a translocation standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh lymphoma 1382 lymphoscintigraphy base of rh

of an oncogene from chromosome 14 to lymphopathia venereum (lı˘mЉfo¯-pa˘thЈe¯- chromosome 18 [t(14;18)]. Most in- a˘) Lymphogranuloma venereum. stances of this lymphoma are indolent, lymphopathy (lı˘m-fo˘pЈa˘-the¯) [ЉϩGr. that is, slowly growing. pathos, disease] Any disease of the Hodgkin’s l. SEE: Hodgkin’s disease. lymphatic system. non-Hodgkin’s l. ABBR: NHL. A lymphopenia (lı˘m-fo¯-pe¯Јne¯-a˘) [ЉϩGr. group of malignant tumors of B or T penia, a lack] A deficiency of lympho- lymphocytes. In 2008, the American cytes in the blood. SYN: lymphocyto- Cancer Society estimated that about penia. 66,100 Americans would be newly di- lymphoplasmapheresis (lı˘mЉfo¯-pla˘zЉma˘- agnosed with the disease. SEE: illus; fa˘r-e¯Јsı˘s) [ЉϩGr. aphairesis, re- Hodgkin’s disease. moval] The removal of lymphocytes and plasma from the blood after it has been withdrawn. The blood is then re- turned to the donor. lymphoplasty (lı˘mЈfo¯-pla˘sЉte¯) [ЉϩGr. plassein, to form] Lymphangioplasty. lymphopoiesis (lı˘mЉfo¯-poy-e¯Јsı˘s) [Љϩ Gr. poiesis, production] The formation of lymphocytes or of lymphoid tissue. lymphopoietic (lı˘mЉfo¯-poy-e˘tЈ˘k)ı [Љϩ Gr. poiein, to produce] Forming lym- phocytes. lymphopoietin (lı˘mЉfo¯-po˘yЈe˘-tı˘n) [ЉϩЉ] Any growth factor that stimulates lym- phocytes to multiply or differentiate. NON-HODGKIN’S LYMPHOMA lymphopoietin 1 (lı˘mЉfo¯-poy’e˘t-ı˘n) Inter- Bizarre-appearing lymphocytes revealing leukin-7. active mitosis (orig. mag. ϫ1000) lymphoproliferative (lı˘mЉfo¯-pro¯-lı˘fЈe˘r-a˘- tı˘v) Concerning the proliferation of SYMPTOMS: Painless lymphadenop- lymphoid tissue. athy in two thirds of patients is the most lymphoreticular (lı˘mЉfo¯-re˘-tı˘kЈu¯-la˘r) [Љ frequent presenting symptom. Others ϩ reticula, net] Pert. to the lympho- have fever, night sweats, loss of 10% or cyte, to the mononuclear phagocyte sys- more of body weight in the 6 months be- tem, and to the tissues that support fore presenting with symptoms of infil- their growth. tration into nonlymphoid tissue. Addi- l. disorder Any benign or malignant tional involvement is in peripheral disease in which lymphocytes or lym- areas such as epitrochlear nodes, the phatic tissues proliferate. Included are tonsillar area, and bone marrow. NHL self-limited proliferation of lymph is 50% more frequent in men than in glands, lymphocytes, and monocytes; in- women of similar age. In most cases the fectious mononucleosis; benign abnor- cause of NHL is unknown, but patients malities of immunoglobulin synthesis; who have received immunosuppressive leukemias; lymphomas such as Hodg- agents have a more than 100 times kin’s disease, lymphosarcoma, reticu- greater chance of developing NHL, lum cell sarcoma, and mycosis fungo- probably owing to the immunosuppres- ides; malignant proliferative response sive agents activating tumor viruses. or abnormal immunoglobulin synthesis TREATMENT: Specific therapy de- such as plasma cell myeloma, macro- pends on the type, grade, and stage of globulinemia, and amyloidosis; histio- the lymphoma. Combination chemo- cytosis; and lipid storage disease. therapies, bone marrow transplanta- lymphoreticulosis, benign, of inoculation tion, radiation therapy, and photochem- (lı˘mЉfo¯-re¯-tı˘kЉu¯-lo¯Јsı˘s) [ЉϩЉϩGr. otherapy may be given, depending on osis, condition] Cat scratch disease. the specific diagnosis. lymphorrhagia (lı˘mЉfo¯-ra¯Јje¯-a˘) [ЉϩGr. lymphomatoid (lı˘m-fo¯Јma˘-toyd) [L. lym- rhegnynai, to burst forth] Flow of pha, lymph, ϩ Gr. oma, tumor, ϩ ei- lymph from ruptured lymph vessels. dos, form, shape] Resembling lym- SYN: lymphorrhea. phoma. lymphorrhea (lı˘mЉfo¯-re¯Јa˘) [ЉϩGr. lymphomatosis (lı˘mЉfo¯-ma˘-to¯Јsı˘s) [Љϩ rhoia, flow] Lymphorrhagia. Љϩosis, condition] Dissemination of lymphorrhoid (lı˘mЈfo¯-royd) Dilated lymphoma throughout the body. lymph channels that resemble hemor- lymphomatous (lı˘m-fo¯Јma˘-tu˘s) 1. Pert. rhoids. to a lymphoma. 2. Affected with lym- lymphosarcoma (lı˘mЉfo¯-sa˘r-ko¯Јma˘) [Љϩ phomata. Gr. sarx, flesh, ϩ oma, tumor] An in- lymphomyxoma (lı˘mЉfo¯-mı˘k-so¯Јma˘) [Љ frequently used term for lymphoma, ϩ Gr. mys, muscle, ϩ oma, tumor] A used most often in veterinary medicine. soft, nonmalignant tumor that contains SYN: lymphoblastoma. short lymphoid tissue. lymphoscintigraphy (lı˘mЉfo¯-sı˘n-tı˘Јgra˘-fe¯) standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh lymphostasis 1383 lysosomal storage disease base of rh

The use of radioactive tracers to identify cells are lysed by enzymes, inorganic the lymphatic drainage basin of a tu- chemicals, or physical means. mor. The technique is used to guide the lyse (lı¯z) [Gr. lysis, dissolution] 1. To surgeon in performing biopsies and in kill. 2. To dissolve; to destroy or frag- the removal of tumors. ment. lymphostasis (lı˘mЉfo˘sЈta˘-sı˘s) [ЉϩGr. lysergic acid diethylamide (lı¯-se˘rЈjı˘k) stasis, a stoppage] Stoppage of the flow ABBR: LSD. A hallucinogenic deriva- of lymph. tive of an alkaloid in ergot. LSD is used lymphotaxis (lı˘mЉfo¯-ta˘kЈsı˘s) [ЉϩGr. legally only for experimental purposes. taxis, arrangement] The effect of at- lysimeter (lı¯-sı˘mЈe˘-te˘r) [Gr. lysis, disso- tracting or repelling lymphocytes. lution, ϩ metron, measure] An ap- lymphotrophy (lı˘m-fo˘tЈro¯-fe¯) [ЉϩGr. paratus for determining solubilities of trophe, nourishment] Lymph nourish- various substances. ment of cells in regions devoid of blood lysin (lı¯Јsı˘n) A substance that causes cell vessels. destruction and death. SEE: antibody. lymphotropic (lı˘mЉfo¯-tro˘pЈı˘k) Attracted lysine (lı¯Јse¯n) ABBR: lys. An amino acid to lymph cells. For example, human im- that is a hydrolytic cleavage product of munodeficiency virus and human T-cell digested protein. It is essential for leukemia-lymphoma virus are lympho- growth and repair of tissues. tropic for CD4ϩ lymphocytes and Ep- l. acetate An amino acid. stein-Barr virus is lymphotropic for B l. hydrochloride An amino acid. lymphocytes. lysis (lı¯Јsı˘s) [Gr., dissolution] 1. The lymphuria (lı˘m-fu¯ Јre¯-a˘) [ЉϩGr. ouron, gradual decline of a fever or disease; the urine] Lymph in the urine. opposite of crisis. 2. The death of cells or Lynch syndrome (lı˘nch) An autosomal microorganisms, caused by antibodies, dominant predisposition to colon cancer complement, enzymes, or other sub- and other solid tumors. People with stances. Lynch I syndrome are susceptible to co- -lysis 1. Suffix meaning to loosen or dis- lon cancer alone, whereas those with solve. 2. In medicine, combining form in- Lynch II syndrome have an additional dicating reduction or relief of. tendency to get cancers of the colon, ova- lysis-centrifugation A technique for de- ries, breasts, and/or uterus. It is also tecting microorganisms in a specimen of known as hereditary nonpolyposis colo- body fluid, in which the cells in the fluid rectal cancer. are mixed in a tube, and then allowed lyo- [Gr. lyein, a loosening or dissolution] to stand (usually for an hour) to allow Combining form meaning to loosen or its cellular components to break down. dissolve. After cellular breakdown (“lysis”) the lyoenzyme (lı¯Љo¯-e˘nЈzı¯m) [Љϩen, in, ϩ tube is centrifuged to concentrate its zyme, leaven] An extracellular enzyme. sediment. The sediment is subsequently spread on culture media. Lyon hypothesis (lı¯Јo˘n) [Mary Lyon, Lysis-centrifugation is used to detect Brit. geneticist, b. 1925] The idea that bacteria, fungi, mycobacteria, and other one of the X chromosomes of the female microorganisms in blood or body fluids. is inactivated during embryogenesis lysogen (lı¯Јso¯-je˘n) [Љϩgennan, to pro- and becomes hyperpyknotic. This chro- duce] Something capable of producing mosome forms, in the cell nucleus, the a lysin. sex chromatin mass, or Barr body. This lysogenesis (lı¯Љso¯-je˘nЈe˘-sı˘s) [Љϩgene- X chromosome remains in this state sis, generation, birth] The production throughout the cell’s progeny so that in of lysin, a cell-destroying antibody. the adult only one X chromosome is ac- lysogenic (lı¯-so¯-je˘nЈı˘k) [ЉϩGr. gennan, tive in each cell. to produce] Producing lysins. Lyons Heart Study A study of the impact lysogeny (lı¯-so˘jЈe˘-ne¯) A special type of of diet on cardiovascular health. It doc- virus-bacterial cell interaction main- umented that people who had suffered tained by a complex cellular regulatory a heart attack could reduce their risk of mechanism. Bacterial strains freshly a second heart attack by following a isolated from their natural environment Mediterranean diet. may contain a low concentration of bac- Љ Ј lyophilization (lı¯-o˘f ı˘-lı¯-za¯ shu˘n) The teriophage. This phage will lyse other process of rapidly freezing a substance related bacteria. Cultures that contain at an extremely low temperature and these substances are said to be lyso- then dehydrating the substance in a genic. high vacuum. SYN: freeze-drying. lysolecithin (lı¯Љso¯-le˘sЈı˘-thı˘n) A substance lyosorption (lı¯Љo¯-sorpЈshu˘n) [Љϩsor- obtained from lecithin through the ac- bere, to suck in] The absorption, in a tion of an enzyme present in cobra colloid, of a substance on the surface of venom. It demyelinates nerves and de- the particles in the dispersed phase. stroys red blood cells. lys lysine. lysosomal storage disease (lı¯Љso¯-so¯Јma˘l) lysate (lı¯Јsa¯t) 1. The products of hydrol- A disease caused by deficiency of specific short ysis. 2. The material that remains when lysosomal enzymes that normally de- standard #49016 - Venes: Taber’s Cyclopedia Medical Dictionary -- 21st Edition -- FADavis

top of rh lysosome 1384 LZ base of rh

grade glycoproteins, glycolipids, or mu- found in neutrophils and macrophages, copolysaccharides. The substances that and in tears, saliva, and other body se- cannot be catabolized accumulate in ly- cretions. It inhibits the growth of bac- sosomes. Specific enzymes account for teria by damaging their cell walls. specific storage diseases. Included in lyssa (lı˘sЈsa˘) [Gr., frenzy] Obsolete term this group are Gaucher’s, Hurler’s, Tay- for rabies. Sachs, Niemann-Pick, Fabry’s, Mor- Lyssavirus (lı˘sЉa˘-vı¯Јru˘s) The genus of quio’s, Scheie’s, and Maroteaux-Lamy the family Rhabdoviridae, which in- diseases. cludes the rabies virus. lysosome (lı¯Јso¯-so¯m) A cell organelle lyssoid (lı˘sЈoyd) [Gr. lyssa, frenzy, ϩ that is part of the intracellular digestive eidos, form, shape] Resembling lyssa or system. Inside its limiting membrane, it rabies. contains a number of hydrolytic en- lyssophobia (lı˘s-o¯-fo¯Јbe¯-a˘) [Љϩphobos, zymes capable of breaking down pro- fear] 1. Fear of going mad, that is, of teins and certain carbohydrates. Lyso- becoming insane. 2. Fear of rabies. somal enzymes contribute to the lytic (lı¯tЈı˘k) Relating to lysis (cellular de- digestion of pathogens phagocytized by struction) or a lysin. a cell, and also to the tissue damage that LZ Landing zone for a helicopter, usually accompanies inflammation. a minimum of 100ϫ 100 feet and free of lysozyme (lı¯Јso¯-zı¯m) [Gr. lysis, dissolu- overhead obstructions such as trees and tion, ϩ zyme, leaven] An enzyme power lines.

short standard