Gynecologic Anatomy and Physiology

CHAPTER 5 © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Gynecologic Anatomy © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FORand Physiology SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Deana Hays Nicole R. Clark The editors acknowledge Nancy J. Hughes, Nancy M. Steele, and Suzanne M. Leclaire, who were the authors of the © Jones & Bartlett Learning,previous edition LLC of this chapter. © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

The women’s health movement encourages (2) the sacrum, and (3) the coccyx. The innomi- women to be© knowledgeable Jones & Bartlett about their Learning, bodies, to nateLLC bones consist of the pubis,© the Jones ischium, & andBartlett Learning, LLC appreciate theNOT unique FOR form SALE and function OR DISTRIBUTIONof the fe- the ilium, all of which are fusedNOT together FOR at SALE the OR DISTRIBUTION male body, and to take responsibility for caring and acetabulum (Corton, 2012). The ilium comprises making decisions about their bodies that will posi- the posterior and upper portion of the innominate tively affect their health. This chapter reviews fe- bone, forming what is known as the iliac crest. It male anatomy and physiology in terms of how they articulates with the sacroiliac joint posteriorly, and © Jonesdirectly & affect Bartlett gynecologic Learning, health and LLC well-being. together with© its Jones ligaments & is Bartlettthe major contributorLearning, LLC Female anatomy and physiology are often re- to pelvic stability. The pubic bones articulate anteri- NOT ferredFOR to SALE as reproductive OR DISTRIBUTION anatomy and physiology. orly with the symphysisNOT FOR pubis SALE and, with OR their DISTRIBUTION inferior Gynecology is defined as the branch of medicine angles from the descending rami, form the impor- dealing with the study of diseases and treatment tant bony landmark of the pubic arch (Figure 5-1). of the female reproductive system. Regardless of The ischial spines are bony prominences that are whether a woman is pregnant or ever intends to clinically important because they are used as land- © Jones & Bartlettreproduce, Learning, her gynecologicLLC care has historically© Jonesmarks when& Bartlett performing Learning, pudendal blocksLLC and in NOT FOR SALE ORfocused DISTRIBUTION on reproduction. This example of namingNOT other FOR medical SALE procedures OR DISTRIBUTION such as sacrospinous lig- provides insight into why women often continue ament suspension (Anderson & Gendry, 2007). The to be essentialized to reproductive functions by ischial spines are also used to assess progression of clinicians. fetal descent during childbirth. The authors of this chapter assume the reader The sacrum and the coccyx shape the posterior has had basic human anatomy and physiology con- portion of the pelvis. The sacrum is formed by the tent. Readers© requiring Jones a &more Bartlett in-depth Learning, discussion fusionLLC of the five sacral vertebrae,© Jones which includes & Bartlett Learning, LLC are referredNOT to general FOR anatomy SALE andOR physiology DISTRIBUTION the important bony landmark ofNOT the sacral FOR prom SALE- OR DISTRIBUTION references. ontory, and joins the coccyx at the sacrococcygeal symphysis. The coccyx is formed by the fusion of four rudimentary vertebrae, is usually movable, PELVIC ANATOMY and is itself a key bony landmark. The true pelvis © Jones & Bartlett Learning, LLC constitutes the© Jonesbony passageway & Bartlett through Learning, which LLC Pelvic Bones and Pelvic Joints NOT FOR SALE OR DISTRIBUTION the fetus mustNOT maneuver FOR to SALE be born ORvaginally. DISTRIBUTION The pelvis is composed of (1) two hip bones called The best-known classification of the female the innominate bones (also known as ox coxae), pelvis is the Caldwell–Moloy (1933) classification,

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78 Chapter 5: Gynecologic Anatomy and Physiology

Sacral promontory Sacroiliac Ilium © Jones &synchondrosis Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Linea terminalis Sacrum

Ischial spine Pubis © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC

NOT FOR SALE OR DISTRIBUTION NOTAcetabulum FOR SALE OR DISTRIBUTION

Iliopectineal eminence Ischium Symphysis pubis © Jones & Bartlett Learning,Ischial LLC tuberosity Obturator© Jones foramen & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

which includes four basic pelvic types: gynecoid, passing laterally through the greater sciatic fora- android, anthropoid, and platypelloid (Figure 5-2). men and inserts in the upper border of the greater © Jones & BartlettEach Learning, pelvic type LLC is classified in accordance with© Jonestrochanter & Bartlettof the femur. Learning, The origin of LLC the obturator NOT FOR SALE ORthe DISTRIBUTIONcharacteristics of the posterior segment of theNOT internus FOR muscleSALE includes OR DISTRIBUTION the pelvic surfaces of the inlet. The development of this classification re- ilium and ischium and the obturator membrane. It sulted in the realization that most pelves are not exits the pelvis through the lesser sciatic foramen, pure types but rather a mixture of types (Kolesova & where it attaches to the greater trochanter of the Vetra, 2012). hip, enabling it to function in external hip rotation (Anderson & Gendry, 2007; Corton, 2012). Pelvic Support© Jones & Bartlett Learning, LLCThe deep perineal space is a pouch© Jones that lies & supe Bartlett- Learning, LLC Pelvic supportNOT structures FOR SALEinclude ORnot DISTRIBUTIONonly the riorly to the perineal membraneNOT (Figure FOR5-3). SALEThis OR DISTRIBUTION muscles and connective tissue of the pelvic floor, deep space is continuous with the pelvic cavity and but also the fibromuscular tissue of the vaginal contains the compressor urethrae and urethrovagi- wall and endopelvic connective tissue (Richter & nal sphincter muscles, the external urethral sphinc- Varner, 2007). The piriformis and obturator internus ter, parts of the urethra and vagina, branches of the © Jonesmuscles & Bartlettand their fasciae Learning, form part LLC of the walls of pudendal artery,© Jones and the &dorsal Bartlett nerve and Learning, vein of LLC NOT theFOR pelvic SALE cavity. OR The DISTRIBUTIONpiriformis muscle originates the clitoris (Corton,NOT 2012).FOR TheSALE perineal OR membrane DISTRIBUTION at the front of the sacrum, near the third and fourth (also known as the urogenital diaphragm, although sacral foramina. This muscle leaves the pelvis by this label is a misnomer) is a sheet made up of dense

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Gynecologic Anatomy and Physiology 79

Platypelloid

© Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE ORfibrous DISTRIBUTION tissue that spans the opening of the anteriorNOT pubococcygeus FOR SALE is furtherOR DISTRIBUTION divided into the pubovag- pelvic outlet. The perineal membrane attaches to inalis, puboperinealis, and puboanalis. the side walls of the vagina and provides support The levator ani and coccygeus muscles form the to the distal vagina and urethra by attaching these pelvic floor, and the related fascia form a support- structures to the bony pelvis (Corton, 2012). ive sling for the pelvic contents. The muscle fibers The levator ani muscle is a critical component insert at various points in the bony pelvis and form of pelvic support;© Jones indeed, & it Bartlettis often considered Learning, the functionalLLC sphincters for the vagina,© Jones rectum, & andBartlett Learning, LLC most importantNOT muscle FOR of SALEthe pelvic OR floor DISTRIBUTION (Corton, urethra. The origin of the levatorNOT ani muscle FOR is SALE the OR DISTRIBUTION 2012). Normally this muscle is in a constant state pubic bone and the adjacent fascia of the obtura- of contraction, providing support for all of the ab- tor internus muscle. Various portions of this mus- dominopelvic contents against intra-abdominal cular sheet insert on the coccyx (the anococcygeal pressures. The levator ani muscle is actually a rapine) and the perineal body, which is a fibrous © Jonescomplex & Bartlettunit of several Learning, muscles LLC with different band lying between© Jones the vagina & Bartlett and the rectum. Learning, The LLC NOT origins,FOR SALEinsertions, OR and DISTRIBUTION functions. The pubococ- different sectionsNOT of FORthe levator SALE ani muscular OR DISTRIBUTION sheet cygeus, puborectalis, and iliococcygeus are the are subdivided based on the exact origin and inser- primary components making up this muscle. The tion of the fibers:

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80 Chapter 5: Gynecologic Anatomy and Physiology

Clitoris Sphincter– Urethra © Jones & Bartlett Learning,membranous urethra LLC Pe©rineal Jones vestibu le& Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOTVagina FOR SALE OR DISTRIBUTION

Perineal membrane Bulbocavernosus muscle Deep transverse Ischiocavernosus perineal muscle © Jones & Bartlett Learning, LLC © Jones & Bartlett muscleLearning, LLC NOT FOR SALE OR DISTRIBUTIONSuperior fascia– NOT FOR SALE ORIschiopubic DISTRIBUTION ramus urogenital diaphragm Vestibular bulb

Levator ani– pubococcygeus muscle Bartholin’s gland © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC Central tendinous point– Ischial tuberosity NOTperineum FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

Levator ani– Superficial transverse iliococcygeus muscle perineal muscle © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC Gluteus maximus NOT FOR SALEmuscle OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Rectum External anal sphincter Fat Anococcygeal body Coccyx

© Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION • The levator prostatae or sphincter vaginae The fan-shaped coccygeus muscle lies anterior fibers form the sling around the vagina and to the sacrospinous ligament, originates from the originate from the posterior surface of the pu- ischial spine, inserts into the lower part of the sa- bis; they insert in the perineal body. crum and coccyx, and works synergistically to aid • The puborectalis© Jones fibers & Bartlettare important Learning, in main- theLLC levator ani muscle. The transverse© Jones perinei & areBartlett Learning, LLC taining NOTfecal continence; FOR SALE they ORoriginate DISTRIBUTION from small straplike muscles that helpNOT support FOR the pelvic SALE OR DISTRIBUTION the posterior surface of the pubis and form a viscera. They originate from the ischial tuberosity, sling around the rectum. pass by the genitalia, and insert in the central ten- • The pubococcygeus fibers originate from the don at the midline. The bulbocavernosus muscles posterior surface of the pubis and insert into aid in strengthening the pelvic diaphragm and © Jonesthe & anococcygealBartlett Learning, rapine. LLC in constricting© theJones urinary & andBartlett vaginal Learning,openings. LLC NOT FOR• The SALE iliococcygeus OR DISTRIBUTION fibers originate from the Their muscleNOT fibers FORoriginate SALE in the ORperineal DISTRIBUTION body obturator internus fascia and the ischium and and surround the vaginal openings as the muscle insert into the anococcygeal rapine. fibers pass forward to insert into the pubis. The

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Gynecologic Anatomy and Physiology 81

© Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC ischiocavernous muscle contracts to cause erec- This conception depicted a woman’s wholeness to tion of the clitorisNOT during FOR sexual SALE arousal. OR ItsDISTRIBUTION muscle be totally related to her genitals,NOT of which FOR the mostSALE OR DISTRIBUTION fibers originate in the tuberosities of the ischium important was her uterus. Consequently, there was and continue at an angle to insert next to the bul- little appreciation for female genitalia. bocavernosus muscle (Anderson & Gendry, 2007; This section describes the multiple organs and Corton, 2012). anatomic structures that constitute a woman’s © Jones & Bartlett Learning, LLC gynecologic anatomy,© Jones which & Bartlettare shown Learning,in a mid- LLC NOT FOR SALE OR DISTRIBUTION sagittal view NOTin Figure FOR 5-4 SALE and Color OR PlateDISTRIBUTION 1. FEMALE GENITALIA Equally important to the discussion of women’s Dr. Nelson Soucasaux, a Brazilian gynecologist, gynecologic anatomy are the multiple nongeni- has devoted much of her writing to the tradition- tal peripheral anatomic structures involved in fe- ally typical and symbolic aspects of women’s sex- male sexual responses, such as salivary and sweat © Jones & Bartlettual Learning, organs, and the LLC importance these views have ©in Jonesglands, &cutaneous Bartlett blood Learning, vessels, and LLC breasts. influencing our understanding of women’s nature. NOT FOR SALE ORAccording DISTRIBUTION to Soucasaux (1993a, 1993b), historicallyNOT External FOR SALE Genital OR Anatomy DISTRIBUTION it was believed that the key to understanding the Vulva female psyche was having a deeper understanding The vulva is the externally visible outer genitalia of woman’s genital functions. By tradition, a wom- (Figure 5-5 and Color Plate 2). It includes the an’s uterus was considered “the fundamental ormons pubis, labia minora, labia majora, clitoris, gan” and was© synonymousJones & withBartlett her genital Learning, organs. urinaryLLC meatus, vaginal opening,© Jones and corpus& Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

FIGURE 5-4 Midsagittal view of a woman’s pelvic organs. © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Fallopian tube

Ovary

Pubic bone © Jones & Bartlett Learning, LLC © JonesUrethra & Bartlett Learning, LLC NOT FORCervix SALE OR DISTRIBUTION NOT FORClitoris SALE OR DISTRIBUTION

Rectum Labium minora Vagina

Labium © Jones & Bartlett Learning, LLC © Jones & Bartlett majoraLearning, LLC NOT FOR SALE OR DISTRIBUTION Sagittal sectionNOT FOR SALE OR DISTRIBUTION

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82 Chapter 5: Gynecologic Anatomy and Physiology

© Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION MonsNOT pubis FOR SALE OR DISTRIBUTION Suspensory Clitoris ligament Urethral opening Labium minora Labium majora Vaginal opening © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC

NOT FOR SALE OR DISTRIBUTION NOT FOR SALEPerineum OR DISTRIBUTION Anus

spongiosum erectile tissue (vestibular bulbs) of the size of the labia minora in women of reproductive labia minora and perineum. The vestibule is inside age. The labia minora are usually more prominent © Jonesthe labia & Bartlettminora and Learning, outside the hymen. LLC On each in children and© Joneswomen who & Bartlett are postmenopausal Learning, LLC side of the vestibule is a Bartholin’s gland, which (Katz, 2012). NOT secretesFOR SALE lubricating OR mucus DISTRIBUTION into the introitus during NOT FOR SALE OR DISTRIBUTION sexual excitement. The mons pubis is the mound- Clitoris like fatty tissue that covers and protects the sym- The clitoris is a sensitive organ that is typically de- physis pubis. During puberty, genital hair growth scribed as the female homologue of the penis in the covers this pad of tissue. male, particularly in terms of its erogenous func- © Jones & Bartlett Learning,The labia majora LLC are fused anteriorly with the© Jonestion (Puppo, & Bartlett 2013). During Learning, the early LLC 1800s, a re- NOT FOR SALE ORmons DISTRIBUTION veneris, or anterior prominence of the symNOT- spected FOR EnglishSALE gynecologist, OR DISTRIBUTION Isaac Baker Brown, physis pubis, and posteriorly with the perineal body theorized that habitual clitoral stimulation was the or posterior commissure. They assist in keeping cause of the majority of women’s diseases because the vaginal introitus closed, which in turn helps it caused an overexcitement of a woman’s nervous prevent infection. The labia minora are surrounded system. As a result, clitorectomy came into favor by the labia majora and are smaller, nonfatty folds as a means to rid women of ailments believed to covered by ©non-hair-bearing Jones & Bartlett skin laterally Learning, and by beLLC caused by clitoral stimulation© (Duffy, Jones 1963; & Hall, Bartlett Learning, LLC vaginal mucosaNOT on FORthe medial SALE aspect. OR The DISTRIBUTION anterior 1998). Fortunately, this theory NOThas long FOR been SALE re- OR DISTRIBUTION aspect of the labia minora forms the prepuce of the futed, and the practice of clitorectomy in the West- clitoris and also assists in enclosing the opening of ern world is rare. the urethra and the vagina. Anatomically, the clitoris is formed from the gen- Women’s vulva vary in size, related to the ital tubercle (Bradshaw, 2012; Martini, Timmons, & © Jonesamount & Bartlettof adipose Learning,tissue, length, LLC and pigment Tallitsch, 2011).© Jones It is 1.5 to & 2 Bartlettcm in length, Learning, consists LLC NOT colorFOR of SALE the labia OR minora DISTRIBUTION or majora, which may be of two cruraNOT and two FOR corpora SALE cavernosa, OR DISTRIBUTION and is light pink, dark pink, shades of gray, peach, brown, covered by a sensitive rounded tubercle known as or black. There is also considerable variation in the the glans (Anderson & Gendry, 2007; Katz, 2012).

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Gynecologic Anatomy and Physiology 83

© Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC The clitoris is a small, sensitive organ that consists Bartholin’s or Greater Vestibular Glands of two pairedNOT erectile FOR chambers SALE and OR is DISTRIBUTIONlocated at The pea-sized Bartholin’s glandsNOT are FOR located SALE at OR DISTRIBUTION the superior portion of the vestibule (Katz, 2012). about the 4 and 8 o’clock positions in the vulvo- These chambers are composed of endothelial- vaginal area, just beneath the fascia. Each gland lined lacunar spaces, trabecular smooth muscle, has an approximately 2-cm duct that opens into a and trabecular connective tissue; they are sur- groove between the labia minora and hymen. The © Jonesrounded & byBartlett a fibrous Learning, sheath, the tunica LLC albuginea. glands, which© are Jones made of & columnar Bartlett cells Learning, that se- LLC NOT TheFOR paired SALE corpus OR spongiosum DISTRIBUTION (bilateral vestibular crete clear orNOT whitish FOR mucus, SALE are stimulated OR DISTRIBUTION dur- bulbs) unite ventrally to the urethral orifice to form ing sexual arousal (Corton, 2012). If the Bartholin’s a thin strand of spongiosus erectile tissue connec- ducts are blocked, infection can occur, resulting tion (pars intermedia) that ends in the clitoris as the in cyst formation that can lead to the develop- glans (Martini et al., 2011). The clitoris is capped ment of an abscess requiring surgical incision and © Jones & Bartlettexternally Learning, by the LLCglans, which is covered by a clito©- Jonesdrainage. & Bartlett Learning, LLC ral hood formed in part by the fusion of the upper NOT FOR SALE ORpart DISTRIBUTIONof the two labia minora. NOTInternal FOR SALE Genital OR Anatomy DISTRIBUTION The clitoris has numerous nerve endings and Urethra contains tissue that fills with blood when the The urethra is a short conduit, approximately 3 to woman is sexually aroused. The blood supply to 5 cm long, extending from the base of the bladder this organ includes the dorsal and clitoral caver- and exiting externally to the vestibule (Katz, 2012). nosal arteries,© whichJones arise & fromBartlett the iliohypogastric Learning, TheLLC urethral mucosa is composed© ofJones stratified & tran Bartlett- Learning, LLC pudendal bed.NOT The FOR autonomic SALE efferent OR DISTRIBUTIONmotor in- sitional epithelium near the urinaryNOT bladder;FOR SALE the OR DISTRIBUTION nervation occurs via the cavernosal nerve of the rest of this structure is lined by a stratified squa- clitoris arising from the pelvic and hypogastric mous epithelium (Katz, 2012; Martini et al., 2011). plexus (Bradshaw, 2012; Katz, 2012). In women, the urethra passes through the urogeni- The labia minora, together with the clitoris, play tal diaphragm, which is a circular band of skeletal © Jonesa critical & Bartlett role in sexual Learning, activity. Because LLC of their muscle that ©forms Jones the sphincter & Bartlett urethrae, Learning, better LLC rich nerve and vascular supply, they are easily sen- NOT FOR SALE OR DISTRIBUTION known as theNOT external FOR urethral SALE sphincter OR DISTRIBUTION(Martini sitized and become engorged with blood during et al., 2011). For a woman to urinate, this sphinc- sexual arousal. This vascular erectile tissue is ca- ter must be voluntarily relaxed—its typical state is pable of becoming significantly enlarged and tense contraction. during sexual excitement. In addition to the great quantity of erectile tissue in the clitoris, erectile tis- Ovaries © Jones & Bartlettsue Learning, is found inside LLC the labia majora and minora,© JonesThe paired & Bartlett ovaries resemble Learning, a large LLC almond in NOT FOR SALE ORaround DISTRIBUTION the vulvovaginal opening, and along theNOT terms FOR of SALEtheir size OR and DISTRIBUTION configuration; they are lower third of the vagina. A very small quantity of located near the lateral walls of the pelvic cavity this tissue can also be found in the vaginal walls (Katz, 2012; Martini et al., 2011) Each ovary mea- and along the urethra. Age-associated female sex- sures approximately 1.5 cm × 2.5 cm × 4 cm and ual dysfunction from decreased clitoral sensitivity weighs 3 to 6 gm (Katz). may be associated with histologic changes in clito- The ovaries produce gametes (also known as ral cavernosal© erectileJones tissue & Bartlett (Katz, 2012). Learning, ova)LLC and the sex hormones known© Jones as estrogen & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTIONand progesterone. The color andNOT texture FOR of theseSALE OR DISTRIBUTION Periurethral Glands organs change with a woman’s age and reproduc- Two Skene’s (paraurethral) glands open directly tive stage. The ovaries in a nulliparous woman are into the vulva and are adjacent to the distal urethra situated on a shallow depression called the ovarian (Katz, 2012). The Skene’s glands, which release fossa, located on either side of the uterus in the © Jonesmucus, & formBartlett a triangular Learning, area of LLCmucous mem- upper pelvic ©cavity. Jones Several & Bartlettligaments support Learning, the LLC NOT braneFOR surroundingSALE OR the DISTRIBUTION urethral meatus from the ovaries. The NOTbroad FORligament SALE is the ORprincipal DISTRIBUTION sup- clitoral glans to the vaginal upper rim or caruncle porting membrane of a woman’s internal genital (Martini et al., 2011). organs, including the fallopian tubes and uterus.

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84 Chapter 5: Gynecologic Anatomy and Physiology

© Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC The remaining ligaments include the mesovarium, the uterus, outward to their openings near the ova- a posterior NOTextension FOR of theSALE broad OR ligament; DISTRIBUTION the ries. Each fallopian tube includesNOT four segments:FOR SALE OR DISTRIBUTION ovarian ligament, which is anchored to the uterus; • The pars interstitialis (intramural portion) pen- and a suspensory ligament, which is attached to etrates the uterine wall. It contains the fewest the pelvic wall. The outermost layer of the ovary is mucosal folds, with the myometrium contrib- composed of a thin layer of cuboidal epithelial cells uting to its muscularis. © Jonescalled &the Bartlett germinal epithelium. Learning, Immediately LLC below © Jones & Bartlett Learning, LLC • The isthmus, the narrow segment adjacent to this epithelial layer is the tunica albuginea, which NOT FOR SALE OR DISTRIBUTION the uterineNOT wall, FOR contains SALE few mucosal OR DISTRIBUTION folds. is made up of collagenous tissue (Katz, 2012). • The middle segment, known as the ampulla, The ovaries comprise three parts: is the widest and longest segment. It contains • An outer cortical region (cortex), which con- extensive branched mucosal folds and is the tains germinal epithelium with oogonia and most common site of fertilization. © Jones & Bartlett Learning,ovarian follicles LLC that number approximately© Jones• The & infundibulum,Bartlett Learning, the funnel-shaped LLC distal NOT FOR SALE OR DISTRIBUTION400,000 at the initiation of puberty (Halvorson,NOT FORsegmen SALEt, opens OR near DISTRIBUTION the ovary but is not at- 2012a) tached to it (Katz, 2012). Very fine fingerlike • The medullary region (medulla), which con- fronds of its mucosal folds, known as fimbriae, sists of connective tissue, myoid-like contrac- project from the opening toward the ovary to tile cells, and interstitial cells help direct the oocyte into the lumen of the fal- • A hilum,© whichJones is the & pointBartlett of entrance Learning, for all LLClopian tube. © Jones & Bartlett Learning, LLC of the ovarian vessels and nerves (Halvorson, The inner surface of each fallopian tube is cov- 2012b; NOTKatz, 2012) FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION ered by fine hairlike structures called cilia that help Two ovarian arteries that arise from the aorta to move ova, when they are released from the descend in the retroperitoneal space and cross in ovaries, along the tube and into the cavity of the front of the psoas muscles and internal iliac ves- uterus. The fallopian tube extends medially and © Jonessels (Katz, & Bartlett 2012). They Learning, enter the infundibulopelvic LLC inferiorly from© theJones infundibulum & Bartlett into the Learning, superior- LLC ligaments, finally reaching the mesovarium found lateral cavity of the uterine opening (Katz, 2012). NOT inFOR the broadSALE ligament. OR DISTRIBUTION The ovarian blood supply The wall NOTof the fallopianFOR SALE tube is OR composed DISTRIBUTION of enters through the hilum, and venous return oc- three layers: mucosa, muscularis, and serosa. The curs through a venous plexus, which collects blood internal mucosa includes the lamina propria and from the adnexal region and drains into the vena ciliated columnar epithelium, which consists pri- cava on the right and the renal vein on the left. marily of two main cell types. On the surface, the © Jones & Bartlett Learning,Innervation of LLC the ovaries is accomplished ©by Jonesabundant & ciliatedBartlett columnar Learning, cells beat LLC in waves to- NOT FOR SALE ORsympathetic DISTRIBUTION and parasympathetic fibers of theNOT ward FOR the SALEuterus, aidingOR DISTRIBUTION in egg transport. Shorter, ovarian plexus that descend along the ovarian mucus-secreting peg cells are interspersed among vessels. These nerves supply the ovaries, broad the ciliated cells. These cilia propel the film they ligaments, and uterine tube. The parasympathetic produce toward the uterus, help transport the fibers in the ovarian plexus arise from the vagus ovum, and hinder bacterial access to the peritoneal nerves. The nerve fibers to the ovaries innervate cavity. The muscularis—the middle layer of the only the vascular© Jones networks, & Bartlett and not Learning,the stroma fallopianLLC tube wall—contains both© Jones inner circular & Bartlett Learning, LLC (Katz, 2012).NOT Because FOR the ovariesSALE and OR surrounding DISTRIBUTION and outer longitudinal smoothNOT muscle FOR layers. SALE Its OR DISTRIBUTION peritoneum are sensitive to pain and pressure, it is wavelike contractions move the ovum toward the important to take great care when examining the uterus. The outer covering of the fallopian tubes is ovaries during the bimanual examination. the serosa; this lubricative layer is part of the vis- ceral peritoneum (Corton, 2012; Katz, 2012). © JonesFallopian & Bartlett Tubes Learning, LLC The ovarian© Jonesand uterine & Bartlettarteries supply Learning, blood LLC NOT TheFOR fallopian SALE tubes OR (also DISTRIBUTION known as the oviducts) to the fallopianNOT tubes. FOR The SALE uterine OR veins, DISTRIBUTION which are paired narrow muscular tubes that extend ap- parallel the path of the arteries, provide the ve- proximately 10 cm from each cornu of the body of nous drainage from this area. Sympathetic and

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Gynecologic Anatomy and Physiology 85

© Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC parasympathetic innervation to the fallopian tubes The nulliparous uterus is approximately 8 cm long, from the hypogastricNOT FOR plexus SALE and pelvic OR splanchnic DISTRIBUTION 5 cm wide, and 2.5 cm thick, andNOT weighs FOR approxi SALE- OR DISTRIBUTION nerves regulates the activity of the smooth muscles mately 40 to 50 gm (Katz, 2012). and blood vessels (Corton, 2012). The uterine wall of the fundus and body consists of three layers: the endometrium, the myometrium, Uterus and the serosa (also known as the adventitia). The © JonesThe uterus & Bartlett is a muscular, Learning, inverted, LLC pear-shaped, uterine mucosa© Joneslayer consists & Bartlett of simple Learning,columnar LLC NOT hollow,FOR SALEthick-walled OR organDISTRIBUTION that opens to the va- epithelium supportedNOT FOR by a laminaSALE propria. OR DISTRIBUTION Simple gina at the cervix and then widens toward the top tubular glands extend from the luminal surface where the uterine tubes enter. Its anatomic regions into the lamina propria. The stratum functionale include the fundus, body, and cervix (Figure 5-6 is the temporary layer at the luminal surface that and Color Plate 3). The fundus is the uppermost responds to ovarian hormones by undergoing cy- © Jones & Bartlettdome-shaped Learning, extension LLC of the uterine body, located© Jonesclic thickening & Bartlett and shedding. Learning, The stratum LLC basale is above the point of entry of the fallopian tubes. The the deeper, thinner, permanent layer that contains NOT FOR SALE ORbody DISTRIBUTION is the enlarged main portion. The cervix is theNOT the FOR basal SALEportions ORof the DISTRIBUTION endometrial glands; this downward constricted extension of the uterus that layer is retained during menstruation. The epithe- opens into the vagina. lial cells lining these glands divide and cover the The uterus is located anteriorly between the uri- raw surface of exposed endometrium that occurs nary bladder and posteriorly between the sigmoid during menstruation. colon and the© rectum.Jones When & Bartlett the bladder Learning, is empty, LLCThe endometrium receives© a Jones double &blood Bartlett Learning, LLC the uterus anglesNOT forward FOR SALEover the ORbladder. DISTRIBUTION As the supply. In the middle of the myometrium,NOT FOR a SALEpair OR DISTRIBUTION bladder fills, the uterus is lifted dorsally and may of uterine arteries branch to form the arcuate ar- become retroflexed, pressing against the rectum. teries. These arteries then bifurcate into two sets

© JonesFIGURE & Bartlett 5-6 Learning, An anterior LLC view of the female internal© Jones genital & anatomy Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTIONshowing the relationships of the ovaries,NOT FORfallopian SALE tubes, OR DISTRIBUTION uterus, cervix, and vagina.

Body of uterus Suspensatory Ampulla Ovarian ligament Fundus of uterus ligament © Jones & Bartlett Learning, LLC © Jones &Uterine Bartlett cavity Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTIONFallopian tube (oviduct)

Ovary Fimbriae Egg cell Round Follicle ligament© Jones & Bartlett Learning, LLC Endometrium© Jones & Bartlett Learning, LLC NOTBroad FOR SALE OR DISTRIBUTION MyometriumNOT FOR SALE OR DISTRIBUTION ligament Perimetrium Cervical canal Cervix

Vagina © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

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86 Chapter 5: Gynecologic Anatomy and Physiology

© Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC of arteries: straight arteries to the stratum basale The vaginal walls can be easily separated because and coiled arteriesNOT FORto the functionalis.SALE OR The DISTRIBUTION double their surfaces are normally moist,NOT lubricated FOR SALEby a OR DISTRIBUTION blood supply to the endometrium is important in basal vaginal fluid. the cyclic shedding of the functionalis; the straight The vaginal wall is composed of three layers: arteries are retained during this process, while the mucosa, muscle, and adventitia. Vaginal epithe- coiled arteries are lost (Anderson & Gendry, 2007). lium is stratified squamous epithelium supported © JonesThe & myometrium Bartlett Learning, is composed LLCof four poorly by a thick lamina© Jones propria. & The Bartlett lamina propria Learning, has LLC NOT definedFOR SALElayers of ORsmooth DISTRIBUTION muscle that are thickest many thin-walledNOT blood FOR vessels SALE that OR contribute DISTRIBUTION to at the top of the uterus. The middle layers contain diffusion of vaginal fluid across the epithelium. the abundant arcuate arteries. The outer layer of The lamina propria of the mucosa contains many the uterus consists of two types of outer coverings: elastic fibers as well as a dense network of blood A cap of serosa covers the fundus, and the body vessels, lymph nodes, and nerve supply. To a much © Jones & Bartlettis surroundedLearning, by LLCan adventitia of loose connective© Joneslesser degree & Bartlett than seen Learning, in the skin, this LLC epithelium tissue (Anderson & Gendry, 2007). undergoes hormone-related cyclic changes, in- NOT FOR SALE ORStructurally, DISTRIBUTION the cervix is made mostly of denseNOT cluding FOR slight SALE keratinization OR DISTRIBUTION of the superficial cells connective tissue, is usually 2.5 to 3 cm in length, during the menstrual cycle (Corton, 2012). The epi- and is covered interiorly by a mucus-secreting cili- thelium has no glands, so it does not secrete mu- ated epithelium at the upper regions and by strati- cus. Release of estrogen causes the epithelium to fied squamous epithelium at the vaginal end. The thicken, differentiate, and accumulate glycogen. opening of the© Jones cervix into & theBartlett vagina occurs Learning, at al- VaginalLLC bacteria metabolize the© glycogen Jones to & lactic Bartlett Learning, LLC most a rightNOT angle FORto the SALElong axis OR of the DISTRIBUTION vagina. acid, causing the typically lowNOT pH of FORthe vaginal SALE OR DISTRIBUTION Uterine blood supply is provided via the uterine environment. and ovarian arteries, with venous return traveling Loose connective tissue containing many elastic via the uterine veins. The hypogastric and ovarian fibers is found underneath the vaginal epithelium, nerve plexuses supply sympathetic and parasym- which has a subdermal layer rich in capillaries. © Jonespathetic & fibersBartlett as well Learning, as carry uterine LLC afferent sen- This rich vascular© Jones supply &is theBartlett source forLearning, vaginal LLC sory fibers on their way to the spinal cord at T11 moisture during sexual stimulation (Soper, 2007). NOT andFOR T12 SALE (Anderson OR & Gendry,DISTRIBUTION 2007; Katz, 2012). Within theNOT epithelium FOR lie SALE the smooth OR DISTRIBUTIONmuscles of the muscularis, which are oriented longitudi- Vagina nally on the outer layer and as circular bundles on The vagina is a thin-walled tube extending from the inner layer. The outer layer—the adventitia— the external vulva to the cervix. Its walls are nor- consists of dense connective tissue with many © Jones & Bartlettmally Learning, in apposition LLC and flattened, but can extend© Joneselastic fibers,& Bartlett which provides Learning, structural LLC support for NOT FOR SALE OR(stretch) DISTRIBUTION greatly, as observed during childbirth. TheNOT the FOR vagina. SALE It also containsOR DISTRIBUTION an extensive nerve sup- length of the vaginal walls varies greatly but on av- ply and venous capillaries. The adventitia is elastic erage the anterior vaginal length is 6 to 9 cm and and rich in collagen, provides structural support to the posterior vaginal length is 8 to 12 cm (Corton, the vagina, and allows for expansion of the vagina 2012; Katz, 2012). The upper portion of the vagina during intercourse and childbirth. encircles the vaginal portion of the cervix. The va- The upper two-thirds of the vagina receives gina touches© the Jones empty bladder& Bartlett on the Learning,ventral and efferentLLC innervation through ©the Jones uterovaginal & Bartlett Learning, LLC superior surface.NOT Inferiorly, FOR SALE it adheres OR to theDISTRIBUTION poste- plexus, which contains both sympatheticNOT FOR and para SALE- OR DISTRIBUTION rior wall of the urethra and opens adjacent to the sympathetic fibers. The pelvic splanchnic nerves labia minora. provide the parasympathetic efferent input to the The internal mucosal layer of the vagina con- uterovaginal plexus. The proximal two-thirds tains traverse folds, known as rugae. This muscu- of the vagina is innervated via the uterovaginal © Joneslar canal & Bartlett extends from Learning, the midpoint LLC of the cervix plexus. The ©lower Jones vagina & receives Bartlett autonomic Learning, ef- LLC NOT toFOR its opening SALE located OR DISTRIBUTIONbetween the urethra and the ferent innervationNOT fromFOR the SALE pudendal OR nerve. DISTRIBUTION The rectum. The mucous membrane lining the vagina distal one-third of the vagina has primarily so- and musculature is continuous with the uterus. matic sensation; this innervation arises from the

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© Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC pudendal nerve and is carried to the sacral spinal some size variation between a woman’s breasts is cord (Katz, NOT2012). FOR SALE OR DISTRIBUTIONnormal. The nipple and areola areNOT made FOR of smooth SALE OR DISTRIBUTION muscle fibers and feature a thick network of nerve endings. BREAST ANATOMY AND PHYSIOLOGY The areola is populated by numerous oil- In Western society, it often seems that a woman’s producing Montgomery’s glands. These glands may © Jonesbreasts & have Bartlett two functions Learning, or roles: LLCone that is sex- form raised bumps© Jones and be &responsive Bartlett to aLearning, woman’s LLC NOT ual,FOR and SALEone that isOR maternal. DISTRIBUTION The breasts are visible menstrual cycle.NOT They FOR protect SALE and lubricate OR DISTRIBUTION the nip- social sex symbols, and they are often a key source ple during lactation. of a woman’s anxiety about her body. Breasts often The nipple usually protrudes out from the sur- define women in both the public and private eye. face of the breast. Some nipples project inward or The breasts—that is, the mammary glands—are are flat with the surface of the breast. Neither flat © Jones & Bartlettlarge, Learning, modified sebaceous LLC glands contained within© Jonesnor inverted & Bartlett nipples appearLearning, to negatively LLC affect a the superficial fascia of the chest wall located over woman’s ability to breastfeed. NOT FOR SALE ORthe pectoralDISTRIBUTION muscles (Katz & Dotters, 2012). EachNOT FORReproductive SALE hormones OR DISTRIBUTION are vital to the devel- consists of a nipple, lobes, ducts, and fibrous and opment of the breast during puberty and lactation. fatty tissue (Color Plate 4). Each breast is com- Prolactin (PRL) and growth hormone (GH) from the posed of 12 to 20 lobes of glandular tissue. The anterior lobe of the pituitary stimulate mammary number of lobes is not related to the size of the gland development. These hormones are aided breast. The ©lobes Jones branch & to Bartlettform 10 to Learning,100 lobules byLLC human placental lactogen ©from Jones the placenta, & Bartlett Learning, LLC per lobe, whichNOT are FOR in turn SALE subdivided OR intoDISTRIBUTION many which stimulates the mammaryNOT gland ductsFOR to SALE be- OR DISTRIBUTION secretory alveoli. These glands are connected to- come active during pregnancy. Estrogen promotes gether by a series of ducts. The alveoli produce the growth of the gland and ducts, while progester- milk and other substances during lactation. Each one stimulates the development of milk-producing lobe empties into a single lactiferous duct that trav- cells. Prolactin, which is released from the anterior © Jonesels out & through Bartlett the nipple. Learning, As a result, LLC there are 15 pituitary, stimulates© Jones milk & production.Bartlett Learning,Oxytocin, LLC to 20 passages through the nipple, resulting in just which is released from the posterior pituitary in re- NOT asFOR many SALE openings OR in the DISTRIBUTION nipple. sponse to suckling,NOT FORcauses SALEmilk ejection OR fromDISTRIBUTION the Fatty and connective tissues surround the lobes lactating breast. of glandular tissue. The amount of fatty tissue de- The lymphatic system in the breast is abun- pends on many factors, including age, the percent- dant and empties the breast tissue of excess fluid. age of body fat relative to total body weight, and Lymph nodes along the pathway of drainage moni- © Jones & Bartlettheredity. Learning, Cooper’s LLC ligaments connect the chest wall© Jonestor for foreign& Bartlett bodies Learning,such as bacteria LLC or viruses. NOT FOR SALE ORto the DISTRIBUTION skin of the breast, giving the breast its shapeNOT Although FOR SALEthe main OR flow DISTRIBUTION moves toward the axilla and elasticity (Katz & Dotters, 2012). The size of and anterior axillary nodes, lymph drainage has the nonpregnant breasts reflects the amount of been shown to pass in all directions from the breast adipose tissue in the breast rather than the amount (Martini et al., 2011). of glandular tissue. The secretory nature of the breasts develops during pregnancy. The nipple© andJones areola & are Bartlett located near Learning, the cen- MENSTRUALLLC CYCLE PHYSIOLOGY© Jones & Bartlett Learning, LLC ter of each breast;NOT theFOR areola SALE is the pigmentedOR DISTRIBUTION area The initiation of menstruation,NOT called FOR menarche, SALE OR DISTRIBUTION surrounding the nipple. These areas usually have a usually happens between the ages of 12 and 15. color and texture that differ from those of the ad- Menstrual cycles typically continue to age 45 to 55, jacent skin. Notably, the color of the nipple–areolar when menopause occurs. Many women find them- complex varies and darkens during pregnancy and selves reluctant to discuss the existence and nor- © Joneslactation. & Bartlett The consistency Learning, of the nippleLLC and are- mality of menstruation.© Jones The & wordBartlett menstruation Learning, has LLC NOT olaFOR may SALE range from OR very DISTRIBUTION smooth to wrinkled and been replacedNOT by a varietyFOR ofSALE euphemisms, OR DISTRIBUTION such as bumpy. The size of the nipples and areolae also the curse, my period, my monthly, my friend, the red varies a great deal from woman to woman, and flag, or on the rag.

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88 Chapter 5: Gynecologic Anatomy and Physiology

© Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC Most women experience deviations from the menarche and just prior to menopause (Ferin & average menstrualNOT FORcycle duringSALE their OR reproductive DISTRIBUTION Lobo, 2012; Fritz & Speroff, 2011).NOT Menstrual FOR cycles SALE OR DISTRIBUTION years. As a result, it is not uncommon for women that occur during the first 1 to 1.5 years after men- to display certain preoccupations regarding their arche are frequently irregular due to the immaturity menstrual bleeding, not only in relation to the reg- of the hypothalamic– pituitary–ovarian axis (Fritz & ularity of its occurrence, but also in regard to the Speroff, 2011). © Jonescharacteristics & Bartlett of the Learning, flow, such as LLCvolume, dura- © Jones & Bartlett Learning, LLC NOT tion,FOR and SALE associated OR signs DISTRIBUTION and symptoms. Unfor- The Hypothalamic–Pituitary–OvarianNOT FOR SALE OR DISTRIBUTION Axis tunately, society has encouraged the notion that a Hypothalamus woman’s normalcy is based on her ability to bear The hypothalamus controls anterior pituitary func- children. This misperception has understandably tions via the secretion of releasing and inhibiting forced women to worry over the most miniscule factors. Together with the pituitary, it manages the changes in their menstrual cycles. Indeed, changes © Jones & Bartlett Learning, LLC © Jonesproduction & Bartlett of hormones Learning, that serve as chemicalLLC mes- in menstruation are one of the most frequent rea- sengers for the regulation of the gynecologic system. NOT FOR SALE ORsons DISTRIBUTION why women visit their clinician. NOT FOR SALE OR DISTRIBUTION The hypothalamus initially releases gonadotropin- Numerous patterns in the secretion of estrogens releasing hormone (GnRH) in a pulsatile manner. and progesterone are possible; in fact, it is difficult On average, the frequency of GnRH secretion is to find two cycles that are exactly the same. Studies once per 60 to 100 minutes during the early follicu- that include women of different ethnicities, occu- lar phase, increases to once per 60 to 70 minutes pations, genetics,© Jones nutritional & Bartlett status, and Learning, age have LLC © Jones & Bartlett Learning, LLC during the middle of the menstrual cycle, and then demonstrated that the length and duration of the NOT FOR SALE OR DISTRIBUTIONdecreases during the luteal phaseNOT (McCartney FOR SALE & OR DISTRIBUTION menstrual cycle vary widely (Assadi, 2013; Johnson Marshall, 2014). The release of GnRH stimulates et al., 2013; Karapanou & Papadimitriou, 2010). the pituitary gland to produce follicle-stimulating Menarche is the most readily evident external hormone (FSH) and luteinizing hormone (LH). Two event that indicates the end of one developmental other hormones necessary for gynecologic health, stage and the beginning of a new one. It is now be- © Jones & Bartlett Learning, LLC estrogen and ©progesterone, Jones & are Bartlett secreted byLearning, the ova- LLC lieved that body composition is critically important ries at the command of FSH and LH. NOT inFOR determining SALE the OR onset DISTRIBUTION of puberty and menstrua- NOT FOR SALE OR DISTRIBUTION tion in young women (Ferin & Lobo, 2012). The Pituitary Gland ratio of total body weight to lean body weight is The oval-shaped, pea-sized pituitary gland is probably the most relevant factor, and individuals located in a small depression in the sphenoid who are moderately obese (i.e., 20–30% above their bone of the skull. It is controlled by the hypo- ideal body weight) tend to have an earlier onset of © Jones & Bartlett Learning, LLC © Jonesthalamus, & Bartlettwhich secretes Learning, releasing LLC factors into menarche (Johnson et al., 2013). Widely accepted NOT FOR SALE OR DISTRIBUTION NOTa FORspecial SALE blood vesselOR DISTRIBUTION network (hypothalamic– standards for distinguishing what are regular ver- hypophyseal portal system) that feeds the pituicytes sus irregular menses, or normal versus abnormal (McCartney & Marshall, 2014). These releasing menses, are generally based on what is consid- factors either stimulate or inhibit the release of ered average and not necessarily typical for every pituitary hormones that travel via the circulatory woman. According to these standards, the normal system to target organs. menstrual cycle© Jones is 21 to &35 Bartlettdays with aLearning, menstrual LLC © Jones & Bartlett Learning, LLC The anterior pituitary synthesizes seven flow lasting NOT4 to 6 days,FOR although SALE a ORflow forDISTRIBUTION as few NOT FOR SALE OR DISTRIBUTION hormones: as 2 days or as many as 8 days is still considered normal (Ferin & Lobo, 2012). • Growth hormone (GH) The amount of menstrual flow varies, with the • Thyroid-stimulating hormone (TSH) average being 50 mL; nevertheless, this volume may • Adrenocorticotropin (ACTH) © Jonesbe as little& Bartlett as 20 mL orLearning, as much as 80 LLC mL. Generally, • Melanocyte-stimulating© Jones & Bartletthormone (MSH) Learning, LLC NOT womenFOR SALE are not awareOR DISTRIBUTION that anovulatory cycles and • ProlactinNOT (PRL) FOR SALE OR DISTRIBUTION abnormal uterine bleeding (changes in bleeding out- • Follicle-stimulating hormone (FSH) side of normal; see Chapter 24) are common after • Luteinizing hormone (LH)

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© Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC FSH and LH (both gonadotropins) are respon- of the pulse, which varies throughout the cycle sible for regulatingNOT FOR gynecologic SALE organ OR DISTRIBUTIONactivities. (Fritz & Speroff, 2011); see ColorNOT Plate FOR 5. SALE OR DISTRIBUTION FSH targets the ovaries, where it stimulates the As noted earlier, under normal physiologic con- growth and development of the primary follicles ditions, GnRH pulses stimulate the release of FSH and results in the production of estrogen and pro- and LH. As a result of this gonadotropic hormone gesterone. The release of FSH from the pituitary is stimulation, the ovarian follicles develop and pro- © Jonesgoverned & Bartlett by a negative Learning, feedback mechanismLLC induce estrogen.© As Jones the amount & Bartlett of estrogen Learning, in the cir- LLC NOT volvingFOR SALEthese steroids. OR DISTRIBUTION In contrast, LH targets the culation increasesNOT and FOR reaches SALE the pituitary OR DISTRIBUTION gland, developing follicle within the ovary; it is respon- it affects the amount of FSH and LH secreted, albeit sible for ovulation, corpus luteum formation, and without significantly affecting the pulse frequency hormone production in the ovaries. Prolactin is (negative feedback). responsible for preparing the mammary gland for When the estrogen level becomes high enough, © Jones & Bartlettlactation Learning, and brings LLC about the synthesis of milk© Jonesthe negative & Bartlett feedback Learning, effect on the pituitaryLLC is re- (McCartney & Marshall, 2014; Molitch, 2014). versed. Now estrogen causes a midcycle positive NOT FOR SALE OR DISTRIBUTION NOTfeedback FOR SALEeffect on OR the DISTRIBUTIONpituitary, which results in Ovaries and Uterus a surge of LH and FSH and causes ovulation. Un- Complex changes occur in the ovaries and the en- der LH influence, the ruptured follicle becomes dometrium as a result of the cyclic fluctuations of the corpus luteum and secretes progesterone. Al- gonadotropic hormones. The endometrium emu- though the presence of progesterone reduces the lates the activities© Jones of the & ovaries;Bartlett thus Learning, whatever frequencyLLC of the hypothalamic© GnRH Jones pulses, & Bartlettthe Learning, LLC happens in NOTthe uterus FOR during SALE the menstrualOR DISTRIBUTION cycle amount of LH released from theNOT pituitary FOR is SALEpro- OR DISTRIBUTION is precisely correlated with whatever is occurring portionally increased to sustain the corpus luteum in the ovaries. The objective of the ovarian cycle and the production of progesterone. In the absence is to produce an ovum, while the objective of the of pregnancy, the corpus luteum degenerates, pro- endometrial cycle is to prepare a site to nourish gesterone levels decline, and menstruation occurs. and maintain the ovum if it becomes fertilized. The © Jones & Bartlett Learning, LLC The GnRH pulses© Jones return &to theBartlett frequency Learning, associ- LLC ovarian cycle includes three distinct phases: the fol- ated with the beginning of the follicular phase and NOT licularFOR phase,SALE ovulation, OR DISTRIBUTION and the luteal phase. The a new cycle beginsNOT (FerinFOR & SALE Lobo, 2012). OR DISTRIBUTION endometrial cycle can be divided into the proliferative phase, the secretory phase, and menstruation The Ovarian Cycle (Fritz & Speroff, 2011). The ovarian cycle comprises three phases: follicu- Hormonal Feedback System lar, ovulatory, and luteal. © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC The menstrual cycle is influenced by a complex in- Follicular Phase NOT FOR SALE ORteraction DISTRIBUTION of hormones. In particular, the monthlyNOT The FOR follicular SALE phase OR is characterizedDISTRIBUTION by the devel- rhythmic functioning of the menstrual cycle de- opment of ovarian follicles and usually lasts from pends on the changing concentrations of gonado- day 1 (first day of menses) to day 14 of the ovarian tropic hormones. The release of LH and FSH from cycle. Folliculogenesis begins during the last few the pituitary depends on the secretion of GnRH days of the previous menstrual cycle and continues from the hypothalamus,© Jones & which Bartlett is modulated Learning, by untilLLC the release of the mature follicle© Jones at ovulation. & Bartlett Learning, LLC the feedbackNOT effects FOR of estrogen SALE and OR progesterone. DISTRIBUTION The decrease in estrogen productionNOT by FOR the corpus SALE OR DISTRIBUTION The hormones LH and FSH, in turn, play impor- luteum and the dramatic fall of inhibin levels al- tant roles in stimulating secretion of estrogen and low the FSH level to rise during the last few days progesterone. of the menstrual cycle. During days 1 through 4 of Almost all hormones are released in short pulses the menstrual cycle, a cohort of primary follicles is © Jonesat intervals & Bartlett of 60 to Learning, 90 minutes throughout LLC most recruited from© aJones pool of &nonproliferating Bartlett Learning, follicles LLC of the menstrual cycle, with these pulses decreas- in response to the increased concentration of FSH NOT ingFOR in frequencySALE OR closer DISTRIBUTION to menstruation. Steroid (Fritz & Speroff,NOT 2011). FOR Follicles SALE that OR have DISTRIBUTION enough hormones modulate the frequency and amplitude granulosa cells will develop receptors for estrogen

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90 Chapter 5: Gynecologic Anatomy and Physiology

© Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC and FSH on the cells of the granulosa layers, and continue to increase. At the end of the follicular LH receptorsNOT on the FOR theca SALE cells. The OR primary DISTRIBUTION role phase, estrogen reaches a bloodNOT level FORof approxi SALE- OR DISTRIBUTION of FSH is to induce the development of increased mately 200 picograms per milliliter (pg/mL); this receptors on the granulosa cells and thereby stim- concentration may be maintained for as long as ulate estrogen production. The preliminary role of 50 hours (Fritz & Speroff, 2011; Halvorson, 2012b). LH is to stimulate the cells’ production of androgen At this critical time, the high estrogen level initiates © Jonesthat will & beBartlett converted Learning, to estrogen by LLC the granulosa a positive feedback© Jones of LH, &generating Bartlett the Learning,preovula- LLC NOT layers.FOR SALE OR DISTRIBUTION tory LH surge.NOT The LH FOR surge, SALE which begins OR DISTRIBUTION34 to 36 Between cycle days 5 and 7, only one dominant hours prior to ovulation and provides a relatively follicle from the cohort of recruited follicles is des- accurate predictor for timing ovulation, is respon- tined to ovulate during the next menstrual cycle. sible for many changes in the follicle selected for As menses progresses, FSH levels decline due to rupture. © Jones & Bartlettthe Learning, negative feedback LLC of estrogen and the negative© JonesInitially & Bartlett the nuclear Learning, membrane LLC around the effects of the peptide hormone inhibin, which is se- oocyte breaks down, the chromosomes progress NOT FOR SALE ORcreted DISTRIBUTION by the granulosa and theca cells of the deNOT- through FOR theSALE rest ofOR the DISTRIBUTIONfirst meiotic division, and veloping follicle (Fritz & Speroff, 2011; Halvorson, the egg moves on to the secondary stage. Meio- 2012b). The decrease in FSH level promotes a more sis ceases at this time and will be initiated again androgenic microenvironment within the adjacent only if the ovum is fertilized. The LH surge stimu- follicles. By the eighth day of the cycle, the domi- lates luteinization of the granulosa cells as well as nant follicle© (Graafian Jones follicle) & Bartlett is producing Learning, more synthesisLLC of progesterone. Progesterone,© Jones in & turn, Bartlett Learning, LLC estrogen thanNOT the FORtotal amount SALE produced OR DISTRIBUTION by the enhances the positive feedbackNOT effect FORof estrogen SALE OR DISTRIBUTION other developing follicles. In response to the domi- on the LH surge and is responsible for promoting nant follicle’s combined production of estrogen enzyme activity in the follicular fluid capable of and FSH, LH receptors develop on its outermost digesting the follicle wall. High levels of LH and granulosa layers. The dominant follicle continues progesterone cause the synthesis of prostaglandins © Jonesto flourish & Bartlett and gradually Learning, moves toward LLC the surface and proteolytic© Jonesenzymes &such Bartlett as collagenase Learning, and LLC of the ovary (see Color Plate 6). The Graafian plasmin. Although the exact mechanism underly- NOT follicleFOR containsSALE theOR ovum DISTRIBUTION and is surrounded by a ing this processNOT is unknown, FOR SALE the activated OR DISTRIBUTION proteo- layer of granulosa cells, which are themselves sur- lytic enzymes and prostaglandins digest collagen in rounded by the specialized theca interna and theca the follicular wall, leading to an explosive release externa cells. of the ovum (oocyte), along with the zona pellu- An oocyte maturation inhibitor (OMI) in the fol- cida and corona radiate surrounding it. At ovula- © Jones & Bartlettlicular Learning, fluid suppresses LLC the final maturation of the© Jonestion, the & ovumBartlett is expelled Learning, and drawn LLC up by the NOT FOR SALE ORdominant DISTRIBUTION follicle until the time of ovulation. TheNOT ciliated FOR fimbriae SALE of OR the fallopianDISTRIBUTION tube to initiate its OMI’s suppressive effects end hours before the LH migration through the oviduct (Ferin & Lobo, 2012; surge that causes ovulation (Halvorson, 2012b). Fritz & Speroff, 2011). New information about the timing of the LH Ovulatory Phase surge and ovulation is available now because of Ovulation is the process whereby the mature ovum the amount of data collected by many clinicians is released ©from Jones the follicle & Bartlett (Halvorson, Learning, 2012b). duringLLC in vitro fertilization. The LH© Jonessurge has &a ten Bartlett- Learning, LLC It occurs approximatelyNOT FOR 10 SALE to 12 hours OR after DISTRIBUTION the LH dency to occur around 3 a.m. NOTin more FOR than two-SALE OR DISTRIBUTION peak—that is, when the highest level of LH is at- thirds of women, and ovulation has been found to tained. Ovulation and the subsequent conversion occur primarily in the morning during the spring of the follicle to the corpus luteum are dependent months and primarily during the evening during on an increased level of estrogen and the LH surge, autumn and winter (Fritz & Speroff, 2011). In the © Joneswhich & marks Bartlett the beginning Learning, of the LLC rapid rise of Northern Hemisphere,© Jones from & BartlettJuly to February, Learning, ap- LLC NOT LH.FOR During SALE the mid-follicular OR DISTRIBUTION phase, the dominant proximately NOT90% of FORwomen SALE will ovulate OR DISTRIBUTIONbetween follicle’s FSH levels diminish, but estrogen levels 4 and 7 p.m. During the spring, 50% of women will

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© Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC ovulate between midnight and 11 a.m. (Fritz & 12 mm in height and increases eightfold in thick- Speroff, 2011,NOT p. 228). FOR SALE OR DISTRIBUTIONness in preparation for implantationNOT ofFOR the fertilSALE- OR DISTRIBUTION ized ovum (Ferin & Lobo, 2012). Luteal Phase Under the influence of LH, the follicle’s granulosa Secretory Phase cells that are left in the ruptured follicle become en- The secretory phase begins at ovulation. When part © Joneslarged, & undergo Bartlett luteinization, Learning, and formLLC the corpus of a 28-day cycle,© Jones it usually & lastsBartlett from day Learning, 15 (the LLC NOT luteum.FOR SALEThe corpus OR luteum DISTRIBUTION continues to function day after ovulation—theNOT FOR exact SALE cycle ORday willDISTRIBUTION vary for approximately 8 days after ovulation. It secretes with cycle length) to day 28. This phase does not increased progesterone and some estrogen that take place if ovulation has not occurred. It tends to start the negative feedback loop to the hypothala- be the most constant phase, in terms of time. mus and pituitary gland, preventing further ovula- During the secretory phase, the glands of the © Jones & Bartletttion Learning, within the current LLC cycle. In the absence of© a Jonesendometrium & Bartlett become Learning, more tortuous LLC and dilated fertilized ovum, luteal cells degenerate, causing a and fill with secretions, primarily as a result of NOT FOR SALE ORdecline DISTRIBUTION in estrogen and progesterone levels, andNOT increased FOR SALE progesterone OR DISTRIBUTIONproduction. The endome- the corpus luteum regresses to become the corpus trium becomes thick, cushiony, and nutritive in albicans. As a result of the regression of the corpus preparation for implantation of the fertilized ovum. luteum, estrogen and progesterone levels decrease In the absence of implantation, the corpus luteum rapidly, removing the negative feedback effect. FSH shrinks, and progesterone and estrogen levels and LH then© begin Jones to increase & Bartlett once again Learning, to initi- subsequentlyLLC decrease. The endometrium© Jones begins& Bartlett Learning, LLC ate the nextNOT menstrual FOR cycle SALE (Ferin OR & Lobo, DISTRIBUTION 2012; to regress toward the end of theNOT secretory FOR phase. SALE OR DISTRIBUTION Fritz & Speroff, 2011). By days 25 to 26, progesterone and estrogen withdrawal results in increased tortuous coiling and The Endometrial Cycle constriction of the spiral arterioles in the thinning The endometrial cycle has three phases: prolifera- layer. © Jonestive, secretory, & Bartlett and menstrual. Learning, LLC Until the ©last Jones decade, &it wasBartlett believed Learning, that de- LLC creased blood flow to the superficial endometrial NOT ProliferativeFOR SALE Phase OR DISTRIBUTION layers resultedNOT in tissueFOR ischemiaSALE ORand resultingDISTRIBUTION The proliferative phase is influenced by estrogen menses. The end of menses was believed to be and entails the regrowth of endometrium after the caused “by longer and more intense waves of va- menstrual bleed. It starts on about the fourth or fifth soconstriction, combined with coagulation mecha- day of the cycle and usually lasts approximately nisms activated by vascular stasis and endometrial © Jones & Bartlett10 Learning, days, ending withLLC the release of the ovum. The© Jonescollapse, & aided Bartlett by rapid Learning, re-epithelization LLC mediated NOT FOR SALE ORproliferative DISTRIBUTION phase involves changes in the endoNOT- by FOR estrogen SALE from theOR emerging DISTRIBUTION new follicular co- metrium, myometrium, and ovaries. These cyclic hort” (Fritz & Speroff, 2011, p. 595). Newer stud- changes, which result from fluctuations in gonad- ies do not support the theory that menstruation otropin and estrogen levels, are characterized by results from vascular events. Rather, the current progressive mitotic growth of the deciduas functio- theory suggests that menstruation is initiated by nalis in response to increasing levels of estrogen enzymatic autodigestion of the functional layer of secreted by ©the Jones ovary. They & Bartlett occur in preparationLearning, theLLC endometrium, which is triggered© Jones by estrogen– & Bartlett Learning, LLC for implantationNOT of FORthe fertilized SALE ovum. OR DISTRIBUTIONprogesterone withdrawal (FritzNOT & Speroff, FOR 2011). SALE OR DISTRIBUTION At the beginning of the proliferative phase, the As estrogen and progesterone levels fall during the endometrium is relatively thin and the endome- days prior to menses, lysosomal membranes be- trial glands are straight, narrow, and short. As the come destabilized, such that the enzymes within phase progresses, the glands become long and tor- them are released into the cytoplasm of the epi- © Jonestuous. & The Bartlett endometrium Learning, becomes LLCthicker as a re- thelial, stromal,© Jones and endothelial & Bartlett cells and Learning, into the LLC NOT sultFOR of theSALE glandular OR hyperplasia DISTRIBUTION and growth of the intercellular NOTspace. TheseFOR enzymes SALE areOR proteolytic: DISTRIBUTION stroma. The endometrium proliferates from 4 to They digest the cells surrounding them as well as

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92 Chapter 5: Gynecologic Anatomy and Physiology

© Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC surface membranes. Their actions result in plate- After ovulation, when progesterone levels are let deposition,NOT release FOR of SALEprostaglandins, OR DISTRIBUTION vascular high, the cervical mucus onceNOT again FOR becomes SALE OR DISTRIBUTION thrombosis, extravasation of red blood cells, and thick, viscous, opaque, and decreased in amount. tissue necrosis in the vascular endothelium (Ferin & This thick mucus is hostile and impenetrable to the Lobo, 2012). Enzymatic action progressively de- sperm. The increased viscosity also reduces the grades the endometrium and eventually disrupts risk of ascending infection at the time of possible © Jonesthe capillaries & Bartlett and venousLearning, system LLCjust under the implantation.© Jones & Bartlett Learning, LLC NOT endometrialFOR SALE surface, OR DISTRIBUTIONcausing interstitial hemor- Increased NOTestrogen FOR levels SALE promote OR stromal DISTRIBUTION vas- rhage and dissolution of the surface membrane cularization and edema and relax the myometrial and allowing blood to escape into the endometrial fibers that supply the cervix. Activated collagenase cavity (Fritz & Speroff, 2011). This degeneration causes the tightly bound collagen bundles to form a continues and extends to the functional layer of the loose matrix, triggering the cervix to become softer © Jones & Bartlettendometrium, Learning, where LLC rupture of the basal arterioles© Jonesa few days & Bartlett prior to and Learning, at ovulation. LLC The external contributes to the bleeding. The concepts about cervical os everts prior to ovulation. Progesterone NOT FOR SALE ORhow DISTRIBUTION the menstrual flow ceases remain unchanged.NOTcauses FOR the SALE cervical OR muscle DISTRIBUTION to retract, the collagen matrix to tighten, and the cervix to become firmer Menstrual Phase (Fritz & Speroff, 2011; Halvorson, 2012b). The menstrual phase begins with the initiation of menses and lasts 4 to 6 days. Prostaglandins initi- Fallopian Tube Mobility ate contractions© Jones of the uterine & Bartlett smooth Learning,muscle and EstrogenLLC stimulates epithelial cell© Jones activity, &result Bartlett- Learning, LLC sloughing ofNOT the degraded FOR SALEendometrial OR tissue, DISTRIBUTION leading in increased cilia movementNOT and secretions FOR SALE in OR DISTRIBUTION ing to menstruation. The composition of menstrual the uterine tubes. These special effects assist ovum fluid comprises desquamated endometrial tissue, red mobility along the fallopian tube following ovula- blood cells, inflammatory exudates, and proteolytic tion. Progesterone reverses these effects, thereby enzymes. Because some of the clotting factors ordi- inhibiting the peristaltic activity of the fallopian tube smooth muscle. © Jonesnarily &found Bartlett in blood areLearning, lysed by lysosomal LLC enzymes © Jones & Bartlett Learning, LLC in the uterus, menstrual blood does not clot (Ferin & Vagina NOT Lobo,FOR 2012; SALE Fritz OR& Speroff, DISTRIBUTION 2011). For 3 to 5 days, NOT FOR SALE OR DISTRIBUTION The changes in hormonal levels of estrogen and 20 to 80 mL (on average) of blood loss occurs. Ap- progesterone have characteristic effects on the proximately 2 days after the start of menstruation, vaginal epithelium. This information becomes im- estrogen stimulates the regeneration of the surface portant when cervical cells are examined under endometrial epithelium, while concurrent simulta- the microscope, as their morphologic differences neous endometrial shedding is occurring. © Jones & Bartlett Learning, LLC © Jonescan be &related Bartlett to specific Learning, stages of theLLC menstrual NOT FOR SALE OR DISTRIBUTION NOTcycle. FOR During SALE the earlyOR DISTRIBUTIONfollicular phase, exfoliated Changes in Organs Due to Cyclic Changes vaginal epithelial cells have vesicular nuclei and Cervix are basophilic. They appear flatter than the cor- After menstruation, the cervical mucus is scant and responding cells in the later phases owing to the viscous. During the late follicular phase, it becomes influence of progesterone, which causes them to clear, copious,© Jonesand elastic. & TheBartlett quantity Learning, of cervical becomeLLC folded and clumped. The© pHJones of the vagina& Bartlett Learning, LLC mucus increases 30-fold compared to the early fol- responds to cyclical changes as estrogen stimulates licular phaseNOT and can FOR stretch SALE to at least OR 6 cm DISTRIBUTION (Ferin & the growth of lactobacilli. LactobacilliNOT FORmetabolize SALE OR DISTRIBUTION Lobo, 2012; Fritz & Speroff, 2011). The cervical glycogen from cervical secretions, producing lactic mucus during this time is clear and stretchable acid that decreases the vaginal pH to a level that (spinnbarkeit). It displays a characteristic ferning assists in protecting the gynecologic tract against appearance during the ovulatory period if observed opportunistic pathogens (Fritz & Speroff, 2011; © Jonesunder & a microscope.Bartlett Learning, LLC Halvorson, 2012b).© Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

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Anderson, J., & Gendry, R. (2007). Anatomy and embryology. In also influences peripubertal body mass index. American Journal J. Berek (Ed.), Berek and Novak’s gynecology (14th ed., pp. 75–127). of Physical Anthropology, 150, 10–20. Philadelphia, PA: Lippincott Williams & Wilkins. Karapanou, O., & Papadimitriou, A. (2010). Determinants of men- Assadi, S. N. (2013). Is being a health-care worker a risk factor for arche. Reproductive Biology and Endocrinology, 5(1), 115–123. © Joneswomen’s & Bartlett reproductive system.Learning, International LLCJournal of Preventive Katz, V. (2012). Reproductive© Jones anatomy. & In Bartlett V. Katz, G. Lentz, Learning, R. Lobob, & LLC Medicine, 4(7), 852–857. D. Gershenson (Eds.), Comprehensive gynecology (6th ed., pp. 39– NOT Bradshaw,FOR SALE K. (2012). OR Anatomic DISTRIBUTION disorders. In B. L. Hoffman, 65). Philadelphia,NOT PA: Mosby FOR Elsevier. SALE OR DISTRIBUTION J. O. Schorge, J. I. Schaffer, L. M. Halvorson, K. D. Bradshaw, Katz, V., & Dotters, D. (2012). Breast diseases. In V. Katz, G. Lentz, F. G. Cunningham, & L. E. Calver (Eds.), Williams gynecology R. Lobo, & D. Gershenson (Eds.), Comprehensive gynecology (2nd ed., pp. 481–505). New York, NY: McGraw-Hill. (6th ed., pp. 301–334). Philadelphia. {A: Mosby Elsevier. Caldwell, W. E., & Moloy, H. C. (1933). Anatomical variations in fe- Kolesova, O., & Vetra, J. (2012). Female pelvic types and age differ- male pelvic bones and their effect on labor with a suggested ences in their distribution. Papers on Anthropology, 21, 147–154. classification. American Journal of Obstetrics & Gynecology, 26, © Jones & Bartlett Learning,479–482. LLC © JonesMartini, F., & Timmons, Bartlett M. J., & Learning, Tallitsch, R. (2011). LLC Human anatomy (7th ed.). San Francisco, CA: Benjamin Cummings. NOT FOR SALE ORCorton, DISTRIBUTION M. (2012). Anatomy. In B. L. Hoffman, J. O. Schorge,NOT FOR SALE OR DISTRIBUTION J. I. Schaffer, L. M. Halvorson, K. D. Bradshaw, F. G. Cunningham, & McCartney, C. R., & Marshall, J. C. (2014). Neuroendocrinology of L. E. Calver (Eds.), Williams gynecology (2nd ed., pp. 918–947). reproduction. In J. F. Strauss & R. L. Barbien (Eds.), Reproductive New York, NY: McGraw-Hill. endocrinology: physiology, pathophysiology, and clinical manage- ment (7th ed., pp. 3–26.) Philadelphia, PA: Saunders. Duffy, J. (1963). Masturbation and clitoridectomy. Journal of the American Medical Association, 186(3), 246–248. doi:10.1001/ Molitch, M. (2014). Prolactin in human reproduction. In jama.1963.63710030028012 J. F. Strauss & R. L. Barbien (Eds.), Reproductive endocrinology: Ferin, M., & Lobo,© Jones R. (2012). & Reproductive Bartlett endocrinology. Learning, In LLCphysiology, pathophysiology, and clinical© managementJones &(7th Bartletted., Learning, LLC G. Lentz, R. Lobo, D. Gershenson, & V. Katz (Eds.), Compre- pp. 45–65). Philadelphia, PA: Saunders. hensive gynecologyNOT (6th FOR ed., pp. SALE 67–95). Philadelphia, OR DISTRIBUTION PA: Mosby Puppo, V. (2013). Anatomy and physiologyNOT of the clitoris, FOR vestibular SALE OR DISTRIBUTION Elsevier. bulbs, and labia minora with a review of the female orgasm and Fritz, M., & Speroff, L. (2011). Clinical gynecologic endocrinology and the prevention of female dysfunction. Clinical Anatomy, 26(1), infertility. Philadelphia, PA: Lippincott Williams & Wilkins. 134–152. Hall, L. A. (1998). The other in the mirror: Sex, Victorians, and his- Richter, H., & Varner, R. (2007). Pelvic organ prolapse. In J. Berek torians. Retrieved from http://www.lesleyahall.net/sexvict.htm (Ed.), Berek and Novak’s gynecology (14th ed., pp. 897–934). Philadelphia, PA: Lippincott Williams & Wilkins. © JonesHalvorson, & L.Bartlett M. (2012a). Amenorrhea. Learning, In B. L. Hoffman, LLC J. O. Schorge, © Jones & Bartlett Learning, LLC J. I. Schaffer, L. M. Halvorson, K. D. Bradshaw, F. G. Cunningham, & Soper, D. (2007). Genitourinary infections and sexually transmitted NOT FORL. E. CalverSALE (Eds.), OR Williams DISTRIBUTION gynecology (2nd ed., pp. 440–459). diseases. In J. NOTBerek (Ed.), FOR Berek and SALE Novak’s gynecology OR DISTRIBUTION (14th ed., New York, NY: McGraw-Hill. pp. 541–559). Philadelphia, PA: Lippincott Williams & Wilkins. Halvorson, L. M. (2012b). Reproductive endocrinology. In Soucasaux, N. (1993a). Archetypal aspects of the female genitals. B. L. Hoffman, J. O. Schorge, J. I. Schaffer, L. M. Halvorson, Museum of Menstruation & Women’s Health. Retrieved from K. D. Bradshaw, F. G. Cunningham, & L. E. Calver (Eds.), Williams http://www.mum.org/sougenit.htm gynecology (2nd ed., pp. 400–439). New York, NY: McGraw-Hill. Soucasaux, N. (1993b). Psychosomatic and symbolic aspects of men- Johnson, W., Choh, A., Curran, J., Czerwinski, S. A., Bellis, C., Dyer, struation. Museum of Menstruation & Women’s Health. Retrieved © Jones & Bartlett Learning,T. D., & Demerath, LLC E. (2013). Genetic risk for earlier menarche© Jonesfrom http://www.mum.org/psychos.htm& Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

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