Female Reproductive System

1. Female Reproductive System Prof. K. Sivapalan.

2. Female Genetalia. • Ovaries. • uterus. • Fallopian tubes. • Cervix • Vagina • Urinary bladder. • urethra. • Labia majora and minora. • Pelvic diaphragm. Female Reproductive System

3. Cyclical Nature of Reproductive Function. • The reproductive years of female is from puberty to menopause, about 30-35 years. • The reproductive function occurs in cycles of about 28 days. It can vary from person to person • It varies from cycle to cycle by hypothalamic and emotional influences. • The cycle is regulated by endocrine function of hypothalamus, anterior pituitary and the ovary. • Ovary and uterus show major cyclical changes. • Day 1 of the cycle is the first day of menstruation because it is easily identifiable. • The period before ovulation is follicular phase and after ovulation is luteal phase. Female Reproductive System

4. Primodial Follicle in Ovary. • Ovum begins development in female fetus. • At birth ovary contains 750,000 primordial follicles, at puberty about 400,000. • It has one primordial ova surrounded by one layer of granulosa cells. • The granulosa cells are believed to secrete oocyte maturation inhibiting factor to keep ovum suspended at the prophase of meiosis Female Reproductive System

5. Ovarian Cycle • Under the influence of FSH about 50 follicles begin developing. • First stage is growth of ovum with two to three fold increase in diameter. • Granulosa cells also proliferate to form leyers. Female Reproductive System

6. Antral and vesicular Follicles • The granulosa cells proliferate rapidly giving rise to many layers of cells. • Spindle cells from ovary intestitium collect around and form theca interna and highly vascular connective tissue develops to form theca externa. • Follicular fluid secreted by follicular cells causes formation of andrum. • It becomes still larger becoming vesicular follicle. • The vesicular fluid is rich in estrogen Female Reproductive System

7. Further Development • The ovum continues to grow reaching 10 fold increase in diameter and 1000 fold increase in mass. • After 7 days one follicle out grows others and all other follicles atrophy. • Estrogen produced by theca cells diffuse out to the circulation. • This is followed by surge of LH secretion. Female Reproductive System

8. Ovulation. • The follicle reaches the diameter of 1 to 1.5 CM by 14th day. This is due to surge in LH secretion. • The wall of the follicle, on the surface of ovary swells rapidly and a small area in the centre, “stigma”, protrudes like nipple. • In 30 minutes fluid begins to ooze and after two minutes the stigma ruptures widely and the follicular fluid is forced into peritoneal cavity. • The fluid takes the ovum surrounded by corona radiata into peritoneal cavity. Female Reproductive System

9. Corpus Luteum. • After ovulation, remaining cells of granulosa and theca interna enlarge. • They become filled with lipid inclusions and appear yellowish- lutenization. • Corpus luteum secrets progesteron and estrogen. • It is about 1.5 CM in diameter by 7 days after ovulation. • Then it begins to involute and becomes corpus albicans by 12 days. Female Reproductive System

10. Cyclical secretion of Hormones • The hypothalamus secrets GnRH • The anterior pituitary secrets LH and FSH. • Overies secrete estrogen, progesteron, inhibin A and inhibin B. • Feed back regulation and the nature of the glands result in cyclical changes in secretion of the hormones. Female Reproductive System

11. Pituitary-Ovary Feed back • At the beginning of the cycle, there is no ovarian hormones. • The FSH and LH are secreted in moderate amounts. • LH stimulates theca cells to produce androstenedione. • FSH stimulates granulosa cells to secrete estrogen into follicular fluid. • Increase in estrogen decreases LH and inhibin reduces FSH • Feed back of estrogen becomes positive at high levels of estrogen • The positive feedback results in burst of LH secretion after 36-48 hours. Female Reproductive System

12. Female Reproductive System

13. Pituitary-Ovary Feed back ctd. • Ovulation occurs after 9 hours of LH peak. • FSH level also rises possibly due to increased GnRH. • The corpus luteum secrets estrogen, progesterone and inhibin. • All three inhibit LH and FSH. • Absence of LH causes regression and atrophy of corpus luteum and secretion of estrogen progesterone and inhibin decreases. • FSH and LH are secreted again. Female Reproductive System

14. Female Reproductive System

15. Estrogen- General. • Secreted by granulosa cells of ovrian follicles, corpus luteum and the placenta. • Transport: • 2% free • balance bound to protein- 60 % Albumin, 38 % Gonadal Steroid-binding Globulin. • Conjugated in liver, secreted in bile, absorbed and excreted in urine. Female Reproductive System

16. Estrogen on Puberty • Enlargement of uterus and vagina. • Narrow shoulders, broad hips, thighs that converge, arms that diverge [wide carrying angle] • Deposition of fat in breasts, buttocks, thighs and subcutaneous tissue. [25 % fat] • All the above are seen in castrate males. • The effect may be action of estrogen and also absence of testosterone. • Pubic and axillary hair- androgens. Female Reproductive System

17. Effects of Estrogen CNS- • Estrous behavior in animals. • Libido increased in human Skin: • Soft, smooth, more vascular Breast: • Proliferation of mammary ducts • Development of stromal tissues. • Deposition of fat. • Pigmentation of areola. Female Reproductive System

18. Estrogen- Effects on Female Genitalia • Facilitates growth of ovarian follicles. • Increases motility of the fallopian tubes. • Increases uterine blood flow. • Increases the amount of uterine muscles and its content of contractile proteins. • Makes myometrium more excitable and active and becomes more sensitive to oxytocin. • Hypertrophy of endometrium on administration and sloughing and bleeding on withdrawal. • Cervical mucus is thin and alkaline. • Cornification of vaginal epithelium. Female Reproductive System

19. Other Actions of Estrogen • Increase angeotensinogen, TBG. • Bone growth [growth spert] and epiphysial closure. • Lack of estrogen- osteoporosis • Salt and water retension. • [premenstrual- aldosteron also elevated] • Liver palms, spider angiomas and enlargement of breast in advanced liver disease are due to circulating estrogen due decreased removal of androstenedione resulting in more estrogen. • Lowers plasma cholesterol and prevents atherogenesis. • Large doses promote thrombosis. Female Reproductive System

20. Progesterone- General. • Secreted by corpus luteum and placenta. • Transport- • 2 % free, 80 % albumin, 18 % to CBG. • Conjugated in liver and excreted in urine. Female Reproductive System

21. Actions of Progesterone. • Secretary changes in endometrium. • Thick mucus from cervix. • In vagina, thick mucus secretion and infiltration of leucocytes in epithelium. • Anti estrogenic effect on myometrium- decrease excitability and sensitivity to oxytocin. • Breast- development of lobules, alveoli and support lactation. • Thermogenic action resulting in increase of basal body temperature on ovulation. • In large doses causes naturesis ? block aldosterone. Female Reproductive System

22. Menstruation. • Menstruation is loss of blood and desquamated endometrium. • It is not purification of female body. • About 70 ml of blood is lost over a period of 3 to 5 days. • This causes increased need of iron for females. • Menorrhagia causes iron defficiency anaemia. Female Reproductive System

23. Menarche. • First menstruation is the first land mark to indicate that the person is capable of reproducing. • It indicates that the cyclical activities are taking effect. • It is not necessary to be followed by either regular ovulation or menstruation for about 2 years. • The uterus, pelvis and the mind are not matured enough for child bearing until after 18 years. Female Reproductive System

24. Menstrual Cycle- Menstrual Flow. • It is the cyclical changes that occur in the endometrium. • The endometrium depends on estrogen for growth and proliferation • It depends on progesteron for secretary changes. • It disintegrates and the arteriols rupture in the absence of both hormones. • The blood and shed stratum functionalae of the endometrium escape through the vagina. Female Reproductive System

25. Proliferative Phase [Follicular Phase] • Endometrium proliferates under influence of estrogen from 5th day of menstruation. • The duration is variable. Female Reproductive System

26. Secretary Phase[Luteal Phase] • After ovulation, progesteron is secreted. • Endometrium becomes highly vascularized, oedematus. • The glands become coiled. • Reducing levels of estrogen and progesteron cause necrosis of endometriom and bleeding [menstruation] again. • The duration is fixed. Female Reproductive System

27. Normal Menstruation. • Contains tissue debris, prostaglandins and large amounts of fibrinolysin. • The menstrual blood does not clot unless it is excessive. Female Reproductive System

28. Anovulatory Cycle. • Sometimes ovulation fails to occur. It is very common for 12 – 18 months after menerche and before menopause. • The corpus luteum does not develop and the effects of progesteron is absent. • Estrogen is secreted for the length of the cycle and withdrawal causes bleeding. Female Reproductive System

29. Indicators of Ovulation. • Abdominal pain • Change in basal body temperature. • Cervical mucus- • Stretched, fern pattern on drying under estrogen. • Secretary changes in endometrium by progesterone. Female Reproductive System