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Chapter 28 Reproductive System (RS)

AP2 Chapter 28 1 Chapter 28 Outline

I. of the Male RS II. Physiology of the male RS III. Anatomy of the RS IV. Physiology of the female RS V. FX of aging on the RS

AP2 Chapter 28 2 The Reproductive System • Controls the development of the structural & fxnal diff between ♀ and ♂ • Not only are reproductive structures different but integumentary, muscular & skeletal system diff’s also exist • : essential to all living (Thus fxnal RS are required to successfully reproduce) • The ♂ RS is designed to prod & deliver it to the ♀ oocyte • The ♀ RS is designed to prod oocytes & receive sperm from the ♂ RS. It is also intimately involved with nurturing the development of the new individual until and well after .

AP2 Chapter 28 3 I. Anatomy of the ♂ RS

AP2 Chapter 28 4 I. Anatomy of the ♂ RS Pathway • Consists of: • Temp sensitive sperm cells 1. Testes develop outside the body 2. Ducts cavity in the testes & ED  Epididymides (ED)  Ductus Differentia (DD) • DD lead from the testes into  the & join with the SV 3. Accessory glands to form the ampullae  (SV)  Gland (PG) • Extensions called  (BG) ejaculatory ducts pass thru 4. Supporting Structures the PG & empty into the  urethra w/in the PG  • Urethra exits the pelvis & passes thru the penis to the outside of the body 5 I. Anatomy of the ♂ RS: Scrotum • Holds testes in compartments separated by an incomplete CT septum • Raphe: external irregular midline ridge on the scrotum that continues to the anus (posteriorly) and Base of the penis (anteriorly) • Outer layers of scrotum: – Skin Raphe – Superficial Fascia (LCT) – Dartos Muscle • 2 muscles control the scrotum’s hold on the testes: – Dartos muscle & cremaster muscle – Hot they both relax & testes move away from the body – Cold and they contract bringing testes toward the warmth of the body

– Normal sperm formation is temperature sensitive 6 I. Anatomy of the ♂ RS: Perineum • A diamond shaped area between the thighs, consists of the urogenital triangle (contains base of the penis & scrotum) & the anal triangle (contains the anal Fig 28.2 pg 1034 opening)

AP2 Chapter 28 7 I. Anatomy of the ♂ RS: Testes: Testicular Histology • Testes: Fig 28.3 pg 1035 – Small ovoid organs w/in the scrotum that are endocrine () and exocrine (sperm cells) glands • Tunica Albuginea (TA): – Outer thick white capsule made of mostly fibrous CT – Septa formed by CT of TA • Lobules: – cone shaped divisions formed Fig 28.3 pg 1035 by internal septa • Sts empty into the tubuli recti • Seminiferous tubules (Sts): (short straight tubes) which in – Tubes that fill the lobules turn empty into the rete testis – Location of sperm development (tubular network) these empty – Stroma (Supporting ) into 15-20 tubules called the contains Interstitial/Leydig efferent ductules (pseudo Cells that secrete testosterone strat. Epi that help sperm exit the testis) 8 I. Anatomy of the ♂ RS: Testes: Descent of the Testes AP2 Chapter 28 Fig 28.4pg1036 9 I. Anatomy of the ♂ RS: Sperm Cell Development • B4 puberty the testes remain relatively simple and unΔ’d • Interstitial cells aren’t prominent and a lumen has yet to develop in the seminiferous tubules • @ 12-14 yrs of age the interstitial cells increase in number & size, a lumen develops in each Fig 28.1 pg 1033 seminiferous tubule, & sperm cell prod’n begins – 74 days for a sperm cell to be prod’d and 50 are spent in the seminiferous tubule AP2 Chapter 28 10 I. Anatomy of the ♂ RS: Sperm Cell Development

Fig 28.3 pg 1035

• : – Sperm cell development – Occurs in the seminiferous tubules  Outside of the Seminiferous tubules are leydig cells (endocrine cells) – Process in wh/germ cells divide & differentiate to form sperm cells – Sustentacular/Sertoli Cells – large cells that extend from the sides to the lumen. Fxn: nourish germ cells and probably w/leydig cells prod a # of such as , , and inhibin • Blood-testes Barrier: tight jxns between sertoli cells req’d b/c sperm cells create surface antigens that can stimulate an immune response 11 I. Anatomy of the ♂ RS: Sperm Cell Development

Fig 28.3 pg 1035

• Leydig cells prod testosterone – This passes into sertoli cells and binds to receptors • Fxn #1: Binding is required for normal fxn • Fxn #2: Testosterone (T) is converted into 2 other steroids: – Dihydrotestosterone (DHT) & (E) • Sertoli cells also secrete -binding (ABH) into the seminiferous tubules • T & DHT bind to ABH and are carried w/other secretions to the • Estradiol & DHT may be the active hormones to promote sperm cell formation 12 Fig 28.5 pg 1040

AP2 Chapter 28 13 I. Anatomy of the ♂ RS: Ducts Sperm

Seminiferous tubules

Tubuli recti

Rete testis

Efferent ductules

Epididymis

Ductus epididymis

Ductus deferens

Ejaculatory duct

Urethra

Exterior of the body AP2 Chapter 28 Figure 28.6 pg 1041 14 I. Anatomy of the ♂ RS: Figure 28.6 pg 1041 Ducts: Epididymis • Made from convoluted efferent ductules that empty into the duct of the epididymis (DoE). – DoE: pseudo strt col epi w/stereocilia (microvilli)  surface area for fluid absorption • Final maturation of sperm occurs here & takes 10-12 days to travel it’s length – Δ’s to sperm include: loss of more cytoplasm, maturation of acrosome, ability to bind zona pellucida of the 2o oocyte • 3 regions: – Head • Sperm from this region are still non- motile – Body – Tail Fig 28.3 pg 1035 • Sperm from this region are motile AP2 Chapter 28 15 I. Anatomy of the ♂ RS: Ducts: Ductus deferens (DD) • DD: emerges from the tail of the epididymis and becomes the Spermatic Cord (SC) – DD, testicular , venous plexus, lymphatic vessels, , • DD Coverings: – External spermatic fascia, cremaster muscle, internal spermatic fascia • Path – Goes up and around the enlarges at the end to form the ampulla and lined with psedo str col epi and smooth muscle to allow for peristaltic contractions to aid in sperm propulsion

Figure 28.6 pg 1041 I. Anatomy of the ♂ RS: Ducts: Ejaculatory Duct (ED)

• Adjacent to the DD ampulla is the seminal vesicle (SV) (sac-shaped gland) • A short duct formed by the joining of the ampulla

& SV is called the Figure 28.6 pg 1041 Ejaculatory Duct – Project into the prostate and end by opening into the urethra

AP2 Chapter 28 17 I. Anatomy of the ♂ RS: Ducts: Urethra • 20 cm long extends from the bladder to the exterior • Males: passageway for – & Reproductive Fluids • Most of urethra str col epi w/ mucus glands throughout • 3 major regions 1. Prostatic Urethra  Transitional epi;  Bladder thru prostate  15-30 prostate ducts & 2 ED’s 2. Membranous Urethra  Shortest from prostate to muscular floor of the pelvis Figure 28.7 pg 1043 3. Spongy Urethra  Longest extends from 2. thru length of the penis; tip strat squ epi

AP2 Chapter 28 18 I. Anatomy of the ♂ RS: Penis • Male of thru wh/sperm is transferred from male to female • Erectile tissue engorgement causes the penis to enlarge and become firm in a process called • 3 columns of erectile tissue: – 2 corpora cavernosa • Lateral & Dorsal • Expands at the base to form the crus of the penis (Attach the penis to the coxae) – 1 corpus spongiosum • Ventral expands over the tip to form the glans penis and expands at the base to form the bulb of the penis at the root

– Root of the penis: Crus & bulb 19 I. Anatomy of the ♂ RS: Penis • Skin of the penis is loosely attached to CT that surrounds erectile columns • Thinner skin covers the glans penis • Well supplies with sensory receptors (esp glans penis) • Foreskin/prepuse covers the glans penis • Primary nerves, , & pass along the dorsal surface. – 1 midline surrounded by 1st an artery then a . – Additional deep arteries are in the corpus cavernosa 20 I. Anatomy of the ♂ RS: Accessory Glands • Seminal Vesicles – Sac-shaped glands located near the ampulla of the DD tapers into a short excretory duct that joins the ampulla of the DD to form the ejaculatory duct – Have a capsule w/fibrous CT & smooth muscle cells • Prostate Gland • Bulbourethral Gland – Glandular & muscular tissue, – Pair of small glands near surrounds prostatic urethra & membranous urethra the 2 ejaculatory ducts – Young males size of a pea – Fibrous CT capsule w/distinct but decreases w/age. Sm muscle cells & numerous Compound mucus gland at fibrous partitions w/sm muscle the base of the penis with that radiate toward the urethra. a single duct entering the – 15-30 prostaic ducts carry spongy urethra secretions to the urethra

21 I. Anatomy of the ♂ RS: Accessory Glands: • Semen: a composite of sperm cells from the testes (5%) & secretions from the seminal vesicles (60%), prostate (30%), & bulbourethral glands (5%) • Emission: discharge of secretions from all of the above into the urethra to form semen • : forceful expulsion of semen from the urethra caused by the contraction of: – Urethra – Skeletal muscles at the floor of the pelvis – Muscles at the base of the penis

AP2 Chapter 28 22 I. Anatomy of the ♂ RS: Accessory Glands: Semen Bulbourethral gland (bug), seminal vesicle (sv), Prostate (pst), & testicular secretions (ts) • B4 ejaculation: • Pre-ejaculate – DD starts peristaltic – bug + urethral muscus contractions to propel its glands secretions toward the – Fxn: ampullae • Lubricates the urethra – Contractions of the • Small amount of ampullae, SV, & lubrication for intercourse ejaculatory duct cause • Neutralization of both the sperm cells & all male urethra & female secretions to move to the prostatic urethra along with pst secretion

AP2 Chapter 28 23 I. Anatomy of the ♂ RS: Accessory Glands: Semen Bulbourethral gland (bug), seminal vesicle (sv), Prostate (pst), & testicular secretions (ts) • ts: • Norm sperm count: 75-400 mill/ml – Sperm cells, a small amount of • Norm ejaculation: 2-5 mls fluid, & metabolic by products • Once sperm is in the correct • sv: environment it becomes more – Thick mucus-like secretions w/ motile. fructose, citric acid, & nutrients to nourish sperm – Most die on the trip to the oocyte – Acrosomal cap helps digest a trail – Fibrinogen for weak coagulation thru the vaginal mucus & past the of semen immediately after “shell” of the oocyte, BUT once ejaculation acrosome is depleted sperm is – Prostaglandins: uterine “dead”. contractions • pst: – Thin milky secretions with a high pH to neutralize urethra & vagina – Clotting factors to convert fibrinogen to fibrin – Fibrinolysin to dissolve coagulation & release sperm into the female reproductive tract

Fig 28.3 pg 1035 24 II. Physiology of ♂ Reproduction

AP2 Chapter 28 25 II. Physiology of ♂ Reproduction

• Dependent on: – Hormonal Mechanisms • Responsible for development of the RS • Maintenance of their fxnal capacities • Development of 2ndary characteristics • Control of sperm formation • Influence over sexual behavior – Neuronal Mechanisms • Primarily involved in sexual behavior • Involved in the control of the sex act

AP2 Chapter 28 26 II. Physiology of ♂ Reproduction Regulation of sex hormone secretion Fig 28.8 1046 • GnRH from the hypothalamus stimulates LH & FSH release from the APit • LH (a.k.a. interstitial cell-stimulating hormone ICSH) stimulates testosterone release from leydig cells • FSH stimulates Sertoli cells to increase spermatogenesis & secrete inhibin – Inhibin has a negative feedback effect on APit to reduce FSH secretion • Testosterone  stimulatory FX on sertoli cells & on development of sex organs & 2ndary sex characteristics

• GnRH: Gonadotropin Releasing Hormones – Negative feedback effect on the • LH: Luteinizing Hormone hypothalamus & Pit to reduce LH & • FSH: Follicle stimulating hormone FSH secretion • Interstitial Cells Leydig Cells • Sustentacular cells Sertoli Cells II. Physiology of ♂ Reproduction Puberty • Human Chorionic Gonadotropin (HCG) – Secreted by the stimulates the synthesis & secretion of testosterone by the fetal testes b4 birth • After birth: no stimulation of testes & even a slight atrophy w/ small secretions of testosterone until puberty (12-14 yrs old) • Puberty: – Age at wh/an individual is capable of – GnRH secretion from hypothalamus is inhibited by small amounts of androgens being secreted until puberty – @ puberty the hypothalamus becomes less sensitive and GnRH secretion increases leading to the LH and FSH secretion • LH sertoli cells stimulated to increase testosterone secretions • FSH increase sperm cell formation • Although testosterone inhibits GnRH somewhat it isn’t enough to stop it

AP2 Chapter 28 28 II. Physiology of ♂ Reproduction: Effects of testosterone • Leydig cells, the adrenal cortex, and possibly sertoli cells produce testosterone • It causes the development of the male sex organs in the embryo & the decent of the testes • It causes the enlargement of the genitals req’d for sperm cell formation • Other FX of testosterone: – Hair growth stimulation (legs, chest, pubic area, axillary region, face, & back) & inhibition (male pattern baldness) causes vellus to become terminal hairs – Skin texture to become rougher/coarser, increase in melanin, increase sebaceous gland secretion (Acne) – Hypertrophy of the & reduced tension in the vocal cords (male voice) – Stimulation of metabolism (a little higher than women) – Stimulates erythropoietin prod’n thus increase RBC count in men – Also has a minor Mineralcorticoid-like effect causes Na+ retention thus increase in overall body fluid volume – Promotes protein synthesis in most tissues ( mass increase) – Rapid growth but also stimulation of the ossification of the epiphyseal plate in the bone (limits growth)

29 II. Physiology of ♂ Reproduction: ♂ sexual behavior & the ♂ sex act • Testosterone – Req’d to initiate & maintain sexual • Pleasurable sensations behavior during sex results in a – Enters the hypothalamus & climatic sensation called surrounding brain & influences their orgasm (wh/is associated fxn resulting in sexual behavior with ejaculation) followed – It may also be converted into other by a resolution phase in steroids that aid sexual behavior wh/ the penis becomes Male Sex Act: flaccid, overall feeling of Series of complex reflexes that result in: satisfaction exists, and – Erection of the penis the male can’t achieve an – Secretion of mucus into the urethra erection or ejaculation for many minutes or hours – Emission (maybe even longer) – Ejaculation

AP2 Chapter 28 30 II. Physiology of ♂ Reproduction: ♂ sexual behavior & the ♂ sex act Sensory AP’s and integration

Produces conscious sexual sensation

Travel up SC to cerebrum

Sacral region of the SC

Reflexes that Pudendal result in the Nerve sex act are integrated here AP’s

Sensory neurons: Genitals 31 II. Physiology of ♂ Reproduction: ♂ sexual behavior & the ♂ sex act Sensory AP’s and integration

Physical Stimuli Psychic Stimuli • Rhythmic massage of the • Additional input to reinforce penis (esp. glans penis) sexual sensations: essential source of sensory – Sight, sound, odor, & thoughts AP’s to initiate an erection & have major FX on sexual ejaculation reflexes – Just as bad thought can have • Additional sensory input to the reverse FX reinforce sexual sensations: – Adolescent dreams are an – Surrounding tissues like the example of this scrotum, anal region, perinea region, & pubic region Impotence/erectile dysfxn (ED): – Engorgement of the Pst & SV inability to achieve or maintain an w/their secretions erection & thus accomplish the male – Irritation of the urethra sex act. (May be mental or physical)

AP2 Chapter 28 32 • 1st component of the male sex act is an

erection (penis enlarged & rigid) • AP travels to the pudendal nerve which travels to the arteries that supply the

erectile tissue. Fig 28.9 pg1049 ♂ sexual behavior & the sex act

• Smooth muscle relaxation causes them to dilate As others constrict shunting the blood into the erectile tissue filling the sinusoids & compressing veins this builds BP in the sinusoids & causes inflation & rigidity of erectile tissue • AP’s for an erection come from the SNS (T2-L1) & PNS (S2-S4) centers* • More imp but if damaged the SNS center can take over

Erection, Emission, & Ejaculation • PNS also causes mucus secretions from mucus glands & 33 II. Physiology of ♂ Reproduction: BUG at base of the penis II. Physiology of ♂ Reproduction: ♂ sexual behavior & the ♂ sex act Erection, Emission, & Ejaculation • Sympathetic nerve centers [SNC] become stimulated as sexual tension builds & this controls emission [accumulation of sperm cells & secretions of the pst & sv in the urethra] • SNC’s APs cause peristaltic contractions of the reproductive ducts & stimulate sv & pst to release their secretions Semen accumulates in the prostatic urethra Prod’s an AP travels to Pudendal Nerve SC Integration Somatic Motor Output Sympathetic Motor Output AP to sk.mscl at base of penis Constriction of internal sphincter (urogenital diaphragm) of the bladder to prevent mixing of urine & semen Rhythmic contractions  semen  urethra

ejaculation Muscle tension throughout the body also increases III. Anatomy of the ♀ RS

AP2 Chapter 28 35 III. Anatomy of the ♀ RS • Consists of: – (lateral) – Uterine Tubes (lateral) – (midline) – Vagina (midline) – External genital organs – Mammary Glands  Ligaments hold everything in place

Fig 28.10 and 28.11 pg1050

AP2 Chapter 28 36 III. Anatomy of the ♀ RS: • Small about 2-3.5 cm long and 1-1.5cm wide • Peritoneal fold called the mesovarium attaches each ovary to the posterior surface of the broad ligament • 2 other ligaments associated with the ovary: – Suspensory ligament: extends from the mesovarium  body wall – Ovarian ligament: attaches the ovary to the superior margin of the uterus • Arteries, veins, & nerves traverse the suspensory ligament & enter ovary thru the mesovarium

AP2 Chapter 28 37 III. Anatomy of the ♀ RS: Ovary: Ovarian Histology Fig 18.12pg1051 AP2 Chapter 28 • • • • • • •

Tunica Albuginea Ovarian/Germinal Numerous smallvesicles Blood vessels,lymphatic Stroma Medulla Cortex epithelium these are: the stromaof thecortex are distributedthroughout the medulla vessels, &nerves – – – – – –

surface coveredby Ovarian follicles CT oftheovary Inner core Outer shell Immediately belowtheepi; contains an Dense fibrousCT peritoneum epi. ofthevisceral :

oocyte   each

enter sim . cub. 38

RS: Ovary: ♀

Ovulation: release of 2ndary oocyte from the ovary III. Anatomy of the III.

Fertilization: sperm cell binds to the PM & penetrates into the cytoplasm of the 2ndary oocyte

Oocyte development & fertilization AP2 Chapter 28 39 Fig 18.13 pg 1052 III. Anatomy of the ♀ RS: Ovary: Follicle Development

• Primordial follicle: 1o oocyte surrounded by a single layer of flat cells called granulosa cells (GC) • @ beginning of puberty some primordial follicles are converted into primary follicles – The oocyte enlarges & granulosa cells become

Fig 28.14 pg 1054 enlarged and cuboidal – Then several layers of granulosa cells form & a layer of clear material is deposited around the 1o oocyte called the zona pelucida. • Every 28 days hormonal Δ’s stimulate some 1o to develop into 2o follicle as vesicles develop w/in GCs • Theca is the capsule that forms around the follicle

40 III. Anatomy of the ♀ RS: Ovary: Follicle Development • Theca interna – Surrounds GCs & aid GC’s in the formation of ovarian hormones • Theca externa – Primarily CT that merges w/ stroma of the ovary • 2o follicle continues to enlarge – Vesicles fuse to form 1 large fluid Fig 28.14 pg 1054 filled chamber called an antrum – At this point this is a mature follicle or Graafian follicle – Oocyte is pushed to the side in a mass of cells (Cumulus mass) the inner most cells around the oocyte are called the corona radiata

41 AP2 Chapter 28 AP2 Chapter 28 42 Follicle becomes the

Only stays fxnal for 10-12 days, unless occurs then it enlarges & becomes the corpus luteum of pregnancy

Corpus albicans continues to shrink & eventually disappears after several mo’s or years

AP2 Chapter 28 43 Fig 28.14 pg 1054 III. Anatomy of the ♀ RS: Uterine Tubes/Fallopian Tubes/ • Mucosa of the UT’s provides nutrients for the oocyte or if fertilization has occurred the developing embryonic mass as is passes thru the tube. • Filled with ciliated cells that helps move both fluid & oocyte/ embryonic mass thru. • Infundibulum: Fig 28.11 pg1050 – The expanded end of the UT • Fimbriae: long thin processes • Opens directly into the peritoneal cavity surrounding the infundibulum to receive the oocyte from the ovary • Ampulla: next region of the UT, • 3 layers of the uterine wall longest portion of the UT a. Serosa: outer formed by peritoneum • Isthmus: region closest to the b. Muscular layer: longitudinal & circular uterus more narrow with thicker smooth muscle walls. c. Mucosa: Mucous membrane of simple • Uterine part of the tube passes cuboidal epi thru the uterine wall & ends at a very small uterine opening 44 III. Anatomy of the ♀ RS: Uterus Walls: 1. Perineum – Serous membrane 2. Myometrium – Smooth muscle 3. – Mucous membrane A. Basal Layer Fig 28.11 pg1050 • Thin deep layer continuous with • Consists of the body, fundus, & myometrium – Cervical mucus glands normally keep B. Fxnal Layer things out of the uterus the exception is during ovulation • Lines cavity & undergoes • Spaces formed by the uterus include changes & the uterine cavity & the cervical canal sloughing • Held in place by: broad, round & during the uterosacral ligament female

45 III. Anatomy of the ♀ RS: Vagina • Female organ of copulation – Receives the penis during intercourse – Allows for menstrual flow – Allows for child birth • Consists of a layer of smooth muscle & an inner lining of moist Strat. Squ. Fig 28.11 pg1050 Epi. – Smooth muscle allows for • Connects the cervix of the stretch during intercourse & uterus to the vestibule • Folded into rugae & – SSEpi: provides protection longitudinal folds from abrasion & contributes to lubrication during intercourse • Hymen covers the vestibular opening of the vagina & can be perforated or not. It can be lost w/o intercourse 46 III. Anatomy of the ♀ RS: • Collectively called the / pudendum External Genitalia • Vestibule: – Space in which the vagina opens posteriorly & the urethra opens Pg 1056 anteriorly • Minora: – Thin, longitudinal skin folds that form a boarder on each side of the vestibule – Prepuce: where the 2 L minora unite to cover the • Labia Majora – 2 prominent rounded folds of skin that are lateral to the L minora, SubQ fat is responsible for its prominence – 2 lateral ends unite anteriorly to form the Mons pubis • Pudendal cleft: – Space between the L majora, most of the time it doesn’t exist because L majora are together concealing the cleft

AP2 Chapter 28 47 III. Anatomy of the ♀ RS: • Clitoris: – Anterior margin of vestibule External Genitalia consisting of shaft & distal glans Pg 1056 with 2 erectile structures (corpus cavernosa), High # of sensory receptors that help initiate & intensify levels of sexual tension • Expand at the base to form the crus of the clitoris • CC is equivalent to the male corpora cavernosa & sexual stimulation results in engorgement wh/makes stimulation easier to accomplish • Bulb of the vestibule – Equivalent to the corpus spongiosum in males – B/comes engorged with blood & is more sensitive during sexual arousal. – Expansion causes narrowing of vaginal orifice & prod’s better contact of the vagina w/penis

during intercourse 48 III. Anatomy of the ♀ RS: External Genitalia

• Paraurethral Glands: – Located between the Pg 1056 urethral tube & the vaginal tube, create mucus secretions • Greater Vestibular Glands: – Located between the hymen & labia minora – Produces small quantity of mucus adds to cervical mucus & provides some lubrication; actual fn unknown • Lesser Vestibular Glands – Located in the vestibule between the openings of the urethra & vagina secrete lubricant III. Anatomy of the ♀ RS: Perineum Fig 28.16 pg 1057

• Urogenital triangle: Anterior; contains external genitalia • Anal triangle: posterior; contains anal opening • Clinical perineum: region between the vaginal opening & anal opening – Episiotomy is an incision to help prevent tearing during childbirth III. Anatomy of the ♀ RS: Mammary Glands • Modified sweat glands that lie superficial to the pectoralis major muscles • Present in both , but normally only fxn in female – Function: • Produce milk to nourish a newborn baby • **ONLY important after reproduction has occurred. • Female Puberty – Estrogens & progesterone cause the enlargement of Fig 28.17 the female pg1057 • Areola: pigmented area in the center of the breast • Nipple: central protruding

region of the area. 51 III. Anatomy of the ♀ RS: • Each : Mammary Glands – Consist of 15-20 lobes • Padded & separated from each other by CT & fat • Each lobe divided into smaller sections: lobules • Alveolar Glands: – Contained in each lobules – Produce milk during • Lactiferous Ducts: – Alveolar glands of each lobule pass the milk to them which open to the outside nipple. – Lactiferous sinus: • Each duct enlarges to form L Fig 28.17 sinus in wh/milk accumulates pg1057 during ejection • Cooper’s Ligament – Support & hold in place 52 III. Anatomy of the ♀ RS: Mammary Glands • Cooper’s Ligament – Support & hold breasts in place – As a woman gets older these ligaments weaken thus the reason older woman’s breasts sag • Nipples are sensitive to tactile stimulation & contain smooth muscle cells that contract causing the nipples to become Fig 28.17 pg1057 erect in response to stimulation. – Respond as erectile tissue during sexual arousal

53 IV. Physiology of ♀ Reproduction A. Under control of hormonal & nervous regulation. B. Development of reproductive organs & normal fxn depend on a # of hormones in the body

AP2 Chapter 28 54 IV. Physiology of ♀ Reproduction: Puberty • Between 11-16 experience their 1st menses called Menarch • Vagina, uterus, uterine tubes, & external genitalia begin to enlarge • Fat deposited around breasts & hips to give the “adult female shape” • Ducts of the breast develop • Pubic & axillary hair grow • Voice changes (lesser extent than men) • Development of sexual drive also begins • B4 puberty hormones levels are low – Estrogen & progesterone secretion by the ovaries are primarily responsible for Δ’s asso w/ puberty – @ puberty GnRH, FSH, and LH are secreted in greater quantities & a pattern of secretion is established – Menstrual cycle is established by: • Cyclic secretion of LH & FSH • Ovulation • Monthly Δ’s in the secretion of E&P

• Resultant Δ’s in the uterus 55 AP2 Chapter 28 IV. Physiology of ♀ Reproduction: Menstrual Cycle • Cyclic changes that occur in sexually mature, nonpregnant females & culminate in menses. – Although this is the classical definition now a days this also includes changes in the hormone secretions, ovary, & uterus • Period of hemorrhage in wh/ the uterine fxnal epi is sloughed & expelled from the uterus. • : – The discharge of blood & elements of the uterine mucus membrane

Fig 28.18 pg 1060

AP2 Chapter 28 56 IV. Physiology of ♀ Reproduction: Menstrual Cycle • Day 1: 1st day of menstration • Menses lasts 4-5 days • Day 14: ovulation in a 28 day cycle – Typically time between ovulation & next menses is 14 days • Follicular phase – Between end of menses & ovulation (rapid development of ovarian follicles) • Proliferative phase – Proliferation of uterine mucosa • Luteal Phase – After ovulation b4 next menses (corpus leuteum) • Secretory Phase – Menstruation & secretion by Fig 28.18 pg 1060 uterine glands

AP2 Chapter 28 57 IV. Physiology of ♀ Reproduction: Menstrual Cycle- Ovarian Cycle

• The events that occur regularly in the ovaries of sexually mature, nonpregnant females during the menstrual cycle • The hypothalamus (HT) & (AP) release the initial hormones that control these events

Fig 28.18 pg 1060 AP2 Chapter 28 58 IV. Physiology of ♀ Reproduction: Menstrual Cycle- Ovarian Cycle Theca interna cells (TIC); Granulosa Cells (GC); Anterior Pituitary (AnP); Estrogen (E); Progesterone (P)

• Early in menstruation hypothalamus secretes GnRH  Stimulates the AP to secrete – LH • Exerts initial FX on TIC & later on GC’s • Stimulates TIC to prod androgens which diffuse to the GC’s – FSH • Exerts main FX on GC’s • Stimulates GC’s to converts androgens from TICs into (E) – Increases the # of LH receptors on both GC’s and TIC’s – GC’s produce (P) which diffuses to the TIC’s and in converted into androgens  which then return to GC’s to be converted into (E) again • Gradually increases the # of LH receptors in GC membrane

AP2 Chapter 28 59 IV. Physiology of ♀ Reproduction: Menstrual Cycle- Ovarian Cycle Theca interna cells (TIC); Granulosa Cells (GC); Anterior Pituitary (AnP); Estrogen (E); Progesterone (P) • Estrogen levels: – Begin at lower levels – At lower levels (E) acts as a negative fdbk loop for the AnP’s secretion of LH & FSH – Later at higher levels – Act as a positive fdbk loop for AnP’s secretion of LH and FSH Immediately B4 ovulation there is a surge of both LH and FSH

LH Surge: FSH Surge: • Occurs immediately B4 ovulation • Initiates ovulation & causes ovulated follicle to b/c • can last for 24 hours corpus luteum • Increase follicle • Causes 1st meiotic division completion sensitivity to LH by • Triggers an event like inflammation in mature follicle increasing the number of • Follicle becomes edematous LH receptors 1. Proteolytic enz’s cause degeneration of • Stimulate the the ovarian tissue around the follicle development of other 2. Follicle ruptures follicles for later ovulation 3. Oocyte & surrounding cells are slowly extruded from the ovary AP2 Chapter 28 60 After ovulation

• Follicle prod’n of • Fertilization estrogen drops & – Outer layer of the remaining GC’s form embryo secretes an LH- the corpus luteum like substance called human chorionic – CL begins to secrete (P) gonadotropin (HCG) and because it is higher than B4 ovulation it fxns – HCG keeps the CL from as a Negative fdbk degenerating thus P&E system on GnRH levels do not drop & secretion from the menses doesn’t occur hypothalamus & thus • No Fertilization also FX the AnP – ~ day 25-26 CL begins to atrophy P&E levels decrease and menses begins

AP2 Chapter 28 61 IV. Physiology of ♀ Reproduction: Menstrual Cycle- Uterine Cycle

• Δ’s that occur primarily in the endometrium of the uterus during the menstrual cycle (other subtle Δ’s occur in the vagina & other structures) • Δ’s in P & E levels cause these Δ’s Fig 28.18 pg 1060 AP2 Chapter 28 62 IV. Physiology of ♀ Reproduction: Menstrual Cycle- Uterine Cycle Pg 1064 Fig 28.20

• Endometrium begins to proliferate w/epi cells dividing rapidly to replace those lost in menses • Internal spiral arteries provide nutrients for the dividing cells

AP2 Chapter 28 63 IV. Physiology of ♀ Reproduction: Menstrual Cycle- Uterine Cycle Pg 1064 Fig 28.20

• These spiral glands begin to secrete small amounts of fluid filled w/glycogen • ~ 7 days after ovulation endometrium is prep’d to receive the embryonic mass • (B4 or after is an unsuitable environment) • As (P) levels rise cellular hypertrophy occurs & cells become secretory • (P) also inhibits smooth muscle contraction

64 IV. Physiology of ♀ Reproduction: Menstrual Cycle- Uterine Cycle Pg 1064 Fig 28.20

• Expulsion from the uterus  cervix  vagina • Loss of (P) can increase contractions of the uterus

AP2 Chapter 28 65 IV. Physiology of ♀ Reproduction: ♀ sexual behavior & the ♀ sex act

• Sexual Drive – Dependent on hormones that comes from things like the & other tissues that convert steroids into androgens • Androgens may effect the brain cells especially those of the hypothalamus to influence sexual behavior – Psychological factors also play a large role in sexual drive

AP2 Chapter 28 66 IV. Physiology of ♀ Reproduction: ♀ sexual behavior & the ♀ sex act • Neural pathways involved in controlling the sexual responses are the same as in ♂ Sensory receptors in the Genitals send AP’s to the sacral region of the SC

From the SC it travels along the ascending In the SC the pathway to the brain reflexes that govern Travels down thru the descending pathway sexual responses back to the sacrum are integrated Thus cerebral influences modulate the sacral reflexes

AP’s are conducted from the SC to reproductive organs by the PNS, SNS and to skeletal muscles by somatic nerve fibers 67 IV. Physiology of ♀ Reproduction: ♀ sexual behavior & the ♀ sex act • PNS stimulation • Tactile stimulation of female genitals – Sexual excitement  + psychological stimuli can trigger erectile tissue of the and orgasm clitoris & around vaginal – Contraction of the vaginal, opening become engorged uterine, & perineal muscles with blood • Contract rhythmically & – Nipples become erect muscle tension of the body – Mucous glands of the increases throughout vestibule secrete a small amount of mucus with a • After sex: large amount coming from – Period of resolution the mucus glands lining characterized by an overall the vaginal wall (these are sense of satisfaction & relaxation not well developed glands) • These secretions • Females can have multiple orgasms provide lubrication & (unlike males) ease the access & • Orgasm isn’t req’d for fertilization movement of the penis during intercourse 68 IV. Physiology of ♀ Reproduction: ♀ & pregnancy • Sperm cells ejaculated into vagina during intercourse  transported thru the cervix, body of the uterus, & uterine tubes to the ampulla – Forces responsible for mvmt swimming ability of the sperm & possibly muscular contractions of the uterus & uterine tubes • Contraction stimulated by oxytocin from AnP & prostaglandins in the semen Fig 28.21 pg 1066

AP2 Chapter 28 69 IV. Physiology of ♀ Reproduction: ♀ fertility & pregnancy • Sperm cells undergo capacitation: – Removal of proteins & modification of glycoproteins of the sperm cell membranes – Acrosomal enz’s  allow penetration of cervical mucus, cumulous mass, zona pelucida, & oocyte plasma membrane • Oocyte lasts 24 hours • Sperm can last up to 6 days – For fertilization to be successful Fig 28.21 pg 1066 must occur 5 days B4 or 1 day after ovulation

AP2 Chapter 28 70 IV. Physiology of ♀ Reproduction: ♀ fertility & pregnancy • • •

Days 7-8afterovulation ( Over thenextfewdayssequentialdivisionsoccur as 1 spermentersthe2 & embryobeginstoimplant caused ittoreachmax thickness&secretoryactivity, endometrium the cellpassesthru uterinetubetouterus –

Fig 29.03pg1084 Outer layeroftheembryo( allowing ittoburrow intoit. enz’s thatdigestcells ofthethickenedendometrium prep’d AP2 Chapter 28 forimplantationE&P have o oocyte

21-22 menstrualcycle trophoblast  fertilization ) secretesproteolytic ) 71 IV. Physiology of ♀ Reproduction: ♀ fertility & pregnancy • Trophoblast: – Secretes Human chorionic gonadotropin (HCG) • HCG causes the corpus luteum to remain fxnal • Thus P & E levels continue to rise • Peaks 8-9 wks after fertilization • Decline by wk 16 & remain relatively constant thru rest of pregnancy • Basis for some pregnancy tests • Initially the corpus luteum is Fig 29.03 pg 1084 responsible for P & E secretion but after 1st 3 mo’s placenta can take over

AP2 Chapter 28 72 Fig28.22 pg 1067

AP2 Chapter 28 73 IV. Physiology of ♀ Reproduction: Menopause

• Women 40-50 – Cycles become less regular & ovulation often doesn’t occur with eventual cessation of cycle – Menopause: cessation of menstrual cycle – Perimenopause/ female climacteric: • Time of onset of irregular periods to complete cessation – Associated w/Δ’s in ovaries • # of follicles  small • Follicles & ovaries become less sensitive/ responsive to LH & FSH stimulation

AP2 Chapter 28 74 IV. Physiology of ♀ Reproduction: Menopause • Side FX of menopause include: – Vasomotor symptoms: hot flashes and palpitations, – Psychological symptoms: increased depression, anxiety, irritability, mood swings and lack of concentration – Atrophic symptoms: vaginal dryness and urgency of urination. • Treatment includes: – Estrogen replacement • Benefits: prevent osteoporosis & possibly colorectal cancer • Risks: prolongs FX of menopause, increased risk of breast, ovarian, & uterine cancer, increased risk of disease; MAY also increase risk of heart attacks, strokes, blood clots – Psychological counseling V. FX if aging on the RS

AP2 Chapter 28 76 Several age related Δ’s occur in the ♂ & ♀ RS

Δ’s in males Δ’s in females • Decrease in • Most significant Δ is – size & weight of the testis menopause – # of Leydig cells • Uterus decreases in size – Sperm prod’n (But still • Vaginal wall thins enough for fertilization) – Sexual activity • Increased risk of • Thinning of seminiferous – Breast cancer tubule wall – Uterine cancer – Ovarian cancer • Prostate gland enlarges as does risk of • Impotence risk increases

AP2 Chapter 28 77