Seminar 2 Abdulrahman aljabr Amenorrhea

Objectives 3- Outline functions of the ovarian hormones— estradiol and progesterone. 4- describe regulation of the female monthly rhythm — interplay between the ovarian and hypothalamic – pituitary hormones.

Function of the Estrogens –Effect on the Primary and Secondary Female Sex Characteristics : o Primary function of the estrogen is cellular proliferation and growth of the tissue of sex organs.

Effect of Estrogen on the Uterus and External sex organs : o The ovaries, fallopian tubes, uterus, vagina all increase in size. o the external genitalia enlarge + deposition of fat in the mons pubis and labia majora + enlargement of the labia minora.

Effect of Estrogen on the vagina : o the vaginal epithelium change from cuboidal to stratified epithelium. more resistance to trauma or infection.

Effect of Estrogen on the Uterus and External Sex Organs : o the uterus increase in size. o proliferation of endometrium stroma and gland aid the nutrition to the ovum.

Effect of Estrogens on the Fallopian Tubes : o Proliferation of the glandular tissues. o increase the number of ciliated epithelium cells. the activity of ciliated cell enhanced : beat toward the uterus. propel the fertilized ovum

Effect of Estrogens on the Breasts : o Development of the stromal tissues of the breasts o Growth of an extensive ductile system o Deposition of fat in the breast.

Effect of Estrogens on the Breasts : o Development of the Lobules and alveoli of the breast. o but progesterone and prolactin cause the ultimate determination of growth and function of these structure

Effect of Estrogens on the bone : o Inhibit osteoclastic activity in the bones o stimulate bone growth due to stimulation of osteoclast genesis inhibitory factor

o Epiphyseal closure : This effect on female is stronger than on male. growth of the female usually earlier than male. Female eunuch who is devoid of estrogen grows taller than a normal female Effect of Estrogens on the bone : Relation between menopause and osteoporosis ?

Effect of Estrogens on Protein Deposition : o Estrogen cause slight increase on total body protein o The enhanced protein deposition caused by testosterone is much powerful than that cause by estrogen.

Effect of Estrogens on Body Metabolism and Fat Deposition : o Estrogen increase the whole body metabolic rate slightly, but only as much as the increase caused by the male sex hormones testosterone. o They also cause deposition of increased quantity of fat in the subcutaneous tissues.

Effect of Estrogens on Body Metabolism and Fat Deposition : o the percentage of body fat in the female is greater than in the male. o In addition, estrogen cause the deposition of fat in the buttocks and thighs which is characteristic of the feminine figure.

Effect of Estrogens on the Skin : o Cause the skin to develop texture that is soft and smooth. o Cause the skin to become more vascular increase warmth of the skin. promotes greater bleeding of the cut surface than is in men.

FUNCTION OF PROGESTERONE

Effect of the Progesterone on the Uterus : o promote secretory change in the uterine endothelium. thus preparing the uterus for implantation of the fertilized ovum. o Decrease the frequent and intensity of uterine contraction helping to prevent expulsion of the implant ovum.

Effect of progesterone on fallopian tubes : o increase secretion of the mucosal lining. These secretion are important for nutrition of the ovum before implantation.

Effect of Progesterone on the Breasts : o development of the tubules and alveoli causing the alveolar cell to proliferate enlarge become secretory in nature. o However it does not secrete milk, milk secretion is stimulated only by prolactin.

Effect of Progesterone on the Breasts : cause the breast to swell due to secretory development in the lobules and alveoli.

Female hormonal system o Hypothalamus : GnRH o Anterior Pituitary gland : FSH LH o Ovaries : Estrogens Progesterone

the regulation of the female monthly rhythm interplay between the ovarian and hypothalamic-pituitary hormones o Hypothalamus secrets GnRH. o GnRH transported by hypothalamus- hypophysial portal system to the anterior pituitary gland. o GnRH causes the anterior pituitary gland to secrets LH and FSH

-ve feedback effects of Estrogen and Progesterone to Decrease LH and FSH Secretion 1.Estrogen in small amount has strong effect. 2.When progesterone is available, the inhibitory effect of estrogen is multiplied 3.The progesterone itself has little effect.

o These feedback operate mainly on the anterior pituitary o they also operate to lesser extent on the hypothalamus to decrease the secretion of GnRH

Inhibin o Secrets from the ovarian corpus luteum (granulosa cells ) to inhibit FSH and LH. o The sertoli cells in testes secrets inhibin. o This hormone has the same effect in male and female – inhibit the secretion of FSH and lesser extent LH. o Therefore it has been believed that inhibin might be important cause in decrease FSH and LH at the end of the cycle

+ve feedback of estrogen before ovulation o The anti. Pituitary gland secrets greatly increase amounts of LH for 1 to 2 days beginning 24 to 48 hrs before ovulation. o There is also much smaller preovulatory surge of FSH as well

+ve feedback of estrogen before ovulation o The cause of this abrupt is not known, however several possible explanations are there : 1)Estrogen has +ve feedback effect of stimulation of LH and FSH (contrast to its normal –ve feedback) 2)The granulosa cells start to secret small but increasing quantities of progesterone a day or so before the surge

+ve feedback of estrogen before ovulation o With of the normal preovulaory of LH surge, ovulation will NOT occur.

Postovulatory phase o corpus luteum secretes large quintities of progesterone and estrogen as well as inhibin. o These hormones have –ve feedback effect on the anti. Pituitary and hypothalamus o Decrease the FSH and LH to the lowest level 3 to 4 days before the onset of the menstruation

Follicular growth phase o 3-4 days before menstruation the corpus lutum has regressed to almost total involution. o Secretion of its hormones decreased to low. o Hypothalamus and anti. Pituitary release from the –ve feedback. o FSH begins to increase and several days after menstruation begins LH secretion increase

Follicular growth phase o These hormones initiate new ovarian follicle growth o progressive increase in the secretion of estrogen. o Estrogen reaches a peak secretion at about 12.5 to 13 days after the onset of new cycle. o During the first 11 to 12 days the level of FSH and LH slightly decrease due to the –ve feedback mainly of estrogen

Follicular growth phase o Then a sudden remarkable increase in the secretion of LH and to lesser extend FSH. o This is the preovulatory surge of LH and FSH which is followed by ovulation.

Preovulatory surge of LH and FSH causes ovulation 11.5 to 12 days after the onset of the cycle there is decline in the secretion FSH and LH. The higher level of estrogen at this time ( or the beginning of progesterone secretion) cause a +ve feedback on the anti. Pituitary which lead to a surge in the secretion of LH and to lower extent FSH.

Preovulatory surge of LH and FSH causes ovulation The great excess of LH level lead to both ovulation and subsequent development of and secretion by corpus luteum

Summary Estrogen functions Female sex organs bone skinProtein and fat deposition Progesterone functions Uterus Fallopian tubes Breasts

Summary

References