Female Reproductive System

1. Female Reproductive System • Reproductive Anatomy • Puberty and Menopause • Oogenesis and the Sexual Cycle • Female Sexual Response • Pregnancy and Childbirth • Lactation 28-

2. Female Reproductive System • Produce and deliver gametes • Provide nutrition and room for fetal development • Give birth • Nourish infant 28-

3. Sex Differentiation • Male and female are indistinguishable for first 8 to 10 weeks of development • Female develops • no testosterone or müllerian-inhibiting factor • causes degeneration of (male) mesonephric duct • paramesonephric duct • develops into uterine tubes, uterus and vagina • genital tubercle becomes clitoris • urogenital folds develop into labia minora • labioscrotal folds into labia majora 28-

4. Ovary • Produces eggs and hormones • almond-shaped, 3 cm x 1.5 cm x 1 cm • tunica albuginea capsule like on testes • cortex produces gametes; medulla holds vessels • Each egg develops in its own fluid-filled follicle and is released by ovulation • Ligaments • attached to uterus by ovarian ligament • attached to pelvic wall by suspensory ligament • contains ovarian artery, vein and nerves • anchored to broad ligament by mesovarium 28-

5. Anatomy of Ovary 28-

6. Secondary Sex Organs • Internal genitalia • duct system of uterine tubes, uterus, vagina • External genitalia • clitoris, labia minora, and labia majora • occupy perineum • accessory glands beneath skin provide lubrication 28-

7. Uterine (Fallopian) Tubes • 10 cm long, muscular tube lined with ciliated cells • Major portions • narrow isthmus near uterus • body (ampulla): middle portion • flares distally into infundibulum with fimbriae • Enclosed in superior margin of broad ligament (mesosalpinx) 28-

8. Epithelial Lining of Uterine Tube 28-

9. Uterus • Thick-walled, pear-shaped muscular chamber that opens into vagina and tilts forward over urinary bladder • internal and external os of cervical canal • openings into uterine tubes in two upper corners • Domed fundus above body of organ 28-

10. Reproductive Tract with Ligaments 28-

11. Histology of Uterine Wall • Perimetrium - external serosa layer • Myometrium - middle muscular layer • 1.25 cm thick in nonpregnant uterus • smooth muscle • produces labor contractions, expels fetus • Endometrium • simple columnar epithelium with thick layer compound tubular glands • stratum functionalis – superficial, shed each period • stratum basalis - deep layer, regenerates a new stratum functionalis with each menstrual cycle 28-

12. Normal/Abnormal PAP Smears 28-

13. Vessels of Reproductive Tract Hormonal changes cause spiral artery vasoconstriction, necrosis of stratum functionalis and menstrual flow 28-

14. Ligaments of Reproductive Tract 28-

15. Vagina • 8-10 cm distensible muscular tube • allows for discharge of menstrual fluid, receipt of penis, semen and birth of baby • Outer adventitia, middle muscularis and inner mucosa • Epithelium • child - simple cuboidal • puberty - estrogens transform to stratified squamous • bacteria ferment glycogen rich cells producing acidic pH • Tilted posteriorly between rectum and urethra • urethra embedded in its anterior wall 28-

16. Vulva (Pudendum) • Mons pubis - mound of fat over pubic symphysis; covered by pubic hair • Labia majora - thick folds of skin • Labia minora - medial, thin hairless folds • form vestibule contains urethral and vaginal openings • form hoodlike prepuce over clitoris • Clitoris - erectile, sensory organ • Vestibular bulbs - erectile tissue around vagina • Greater and lesser vestibular and paraurethral glands open into vestibule for lubrication 28-

17. Female Perineum Showing Vulva 28-

18. Components of Female Perineum 28-

19. Breasts • Overlies pectoralis major • conical body, nipple at apex • axillary tail contains many lymphatic vessels • Nipple surrounded by areola • dermal blood vessels closer to surface • melanocytes darken during pregnancy • smooth muscle contracts wrinkling skin and erecting nipple in response to cold, touch and arousal • Suspensory ligaments from skin, muscle • Nonlactating breast has little glandular tissue 28-

20. Anatomy of Lactating Breast 28-

21. Anatomy of Lactating Breast 28-

22. Sagittal Section of Breast 28-

23. Breast Cancer • 1 out of 8 American women • Tumors begin with cells from mammary ducts • may metastasize by lymphatics • Symptoms may include palpable lump, skin puckering, skin texture and drainage from nipple • Most breast cancer is nonhereditary • some stimulated by estrogen • Risk factors include • aging, ionizing radiation, carcinogenic chemicals, alcohol, smoking and fat intake • 70% lack risk factors 28-

24. Cancer Screening and Treatment 28-

25. Puberty • Begins at age 9-10 (US) • Triggered by rising levels of GnRH • stimulates anterior lobe of pituitary to produce • follicle-stimulating hormone (FSH) • luteinizing hormone (LH) • Follicles develop and begin to secrete estrogen and progesterone 28-

26. Puberty • Thelarche - development of breasts • Pubarche - growth of pubic and axillary hair; apocrine and sebaceous glands • Menarche - first menstrual period • requires at least 17% body fat in teenager, 22% in adult • leptin stimulates gonadotropin secretion • improved nutrition (↑ body fat) has lowered avg. age of onset to 12 • Female hormones secreted cyclically and in sequence 28-

27. Climacteric • Midlife change in hormone secretion • due to age related depletion of follicles • occurs with menopause (cessation of menstruation); average age of 52 • Results • atrophy of uterus, vagina and breasts • skin becomes thinner, bone mass declines, and risks of cardiovascular disease increase • hot flashes (sudden dilation of cutaneous arteries) occur several times a day • HRT = hormone replacement therapy 28-

28. Oogensis and Sexual Cycle • Reproductive cycle - events occurring between fertilization and birth • Sexual cycle - events recurring every month when pregnancy does not occur • ovarian cycle = events in ovaries • menstrual cycle = parallel changes in uterus 28-

29. Oogenesis • Monthly event produces haploid egg by meiosis • Embryonic development of ovary • female germ cells arise from yolk sac • differentiate into oogonia, multiply • transform into primary oocytes - early meiosis I • most degenerate (atresia) by childhood • by puberty 400,000 oocytes remain • FSH stimulates completion of meiosis I, produces secondary oocyte and 1st polar body • proceeds to meiosis II and ceases until fertilization • after fertilization , releases 2nd polar body 28-

30. Oogenesis and Follicle Development 28-

31. Sexual Cycle • Averages 28 days, ranges from 20 to 45 • Hormone cycle: hierarchy of control • hypothalamus→ pituitary → ovaries → uterus • Follicular phase (2 weeks) • menstruation occurs during first 3 to 5 days of cycle • uterus replaces lost endometrium and follicles grow • Luteal phase (2 weeks) • corpus luteum stimulates endometrial thickening • endometrium lost without pregnancy 28-

32. Ovarian Cycle - Follicular Phase • Menstruation (day 1) to ovulation(14) (variable) • Difficult to predict date of ovulation • Contains menstrual and preovulatory phases 28-

33. Ovarian Cycle - Preantral Phase • Discharge of menstrual fluid (days 1-5) • Before follicle develops antrum • primordial and primary follicles 28-

34. Ovarian Cycle - Antral Phase • Day 6 to 14, one dominant follicle advances to mature (graafian) follicle; secretes estrogen 28-

35. Ovarian Cycle - Ovulation • Mature follicle ruptures, releases oocyte influenced by LH 28-

36. Histology of Ovarian Follicles 28-

37. Pituitary-Ovarian Axis 28-

38. Ovarian Cycle - Luteal Phase • Corpus luteum - forms from ruptured follicle, under influence of LH; secretes progesterone 28-

39. Menstrual Cycle - Proliferative Phase • Day 6-14 rebuild endometrial tissue • mitosis occurs in stratum basalis • result of estrogen from developing follicles 28-

40. Menstrual Cycle - Secretory Phase • Further thickening of endometrium due to secretion and fluid accumulation -- not mitosis • Due to progesterone stimulation of glands 28-

41. Menstrual Cycle Premenstrual Phase • Involution of corpus luteum, progesterone falls • spiral arteries constrict causes endometrial ischemia • stratum functionalis sloughs 28-

42. Menstrual Cycle - Menstrual Phase • Blood, serous fluid and endometrial tissue are discharged 28-

43. Female Sexual Response 28-

44. Pregnancy and Childbirth • Gestation (pregnancy) • lasts an average of 266 days from conception to childbirth • gestational calendar measured from first day of the woman’s last menstrual period (LMP) • Birth predicted 280 days from LMP • 3 three month intervals called trimesters 28-

45. Prenatal Development • Age based terminology • blastocyst is less than 2 weeks old • embryo is from 2 to 8 weeks old • fetus is 9 weeks to birth • neonate - newborn to 6 weeks 28-

46. Hormones of Pregnancy • HCG (human chorionic gonadotropin) • secreted by trophoblast within 9 days of conception • prevents involution of corpus luteum • Estrogens • increases to 30 times normal before birth • corpus luteum is source for first 12 weeks until placenta takes over • causes uterine, mammary duct and breast enlargement 28-

47. Hormones of Pregnancy • Progesterone • secreted by placenta and corpus luteum • suppresses secretion of FSH and LH preventing follicular development • prevents menstruation, thickens endometrium • stimulates development of acini in breast • HCS (human chorionic somatomammotropin) • secreted from placenta in direct proportion to its size • ↓ mother’s glucose usage and ↑ release of fatty acids 28-

48. Hormones of Pregnancy • Aldosterone secretion rises • fluid retention ↑ mother’s blood volume • Endocrine organs • thyroid gland increases 50% in size • ↑ BMR of mother • parathyroid glands enlarge • stimulate osteoclasts to release additional calcium from mother’s bones 28-

49. Hormone Levels and Pregnancy 28-

50. Adjustments to Pregnancy 28-