Female Reproductive System Prof. K. Sivapalan.

Female Reproductive System Female Genetalia. Ovaries. uterus. Fallopian tubes. Cervix Vagina Urinary bladder. urethra. Labia majora and minora. Pelvic diaphragm. 22014 Female Reproductive System

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. 22014 Female Reproductive System

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 22014 Female Reproductive System

Female Reproductive System 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. 22014 Female Reproductive System

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 22014 Female Reproductive System

Female Reproductive System 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. 22014 Female Reproductive System

Female Reproductive System 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. 22014 Female Reproductive System

Female Reproductive System 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. 22014 Female Reproductive System

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. 22014 Female Reproductive System

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. 22014 Female Reproductive System

Female Reproductive System 22014 Female Reproductive System

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. 22014 Female Reproductive System

Female Reproductive System 22014 Female Reproductive System

Female Reproductive System 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. 22014 Female Reproductive System

Female Reproductive System 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. 22014 Female Reproductive System

Female Reproductive System 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. 22014 Female Reproductive System

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. 22014 Female Reproductive System

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. 22014 Female Reproductive System

Progesterone- General. Secreted by corpus luteum and placenta. Transport- 2 % free, 80 % albumin, 18 % to CBG. Conjugated in liver and excreted in urine. 22014 Female Reproductive System

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. 22014 Female Reproductive System

Female Reproductive System 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. 22014 Female Reproductive System

Female Reproductive System 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. 22014 Female Reproductive System

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. 22014 Female Reproductive System

Proliferative Phase [Follicular Phase] Endometrium proliferates under influence of estrogen from 5th day of menstruation. The duration is variable. 22014 Female Reproductive System

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. 22014 Female Reproductive System

Female Reproductive System Normal Menstruation. Contains tissue debris, prostaglandins and large amounts of fibrinolysin. The menstrual blood does not clot unless it is excessive. 22014 Female Reproductive System

Female Reproductive System 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. 22014 Female Reproductive System

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. 22014 Female Reproductive System