The document summarizes the uterine (menstrual) cycle. It describes the three phases: menstruation where the endometrium breaks down, the proliferative phase where the endometrium grows under estrogen stimulation, and the secretory phase where progesterone stimulates uterine gland secretion. It also outlines the roles of the hypothalamus, pituitary gland, ovaries, estrogen, and progesterone in regulating the cycle. If fertilization does not occur, the corpus luteum degenerates and stops producing hormones, causing menstruation and restarting the cycle.

1. The Uterine (Menstrual) CycleGroup 8: Diana Hegazin, Stacey Dust, Deborah Ondimu, Gayle Woods, DerejeGemeda, TochiOhaleThat’s Ursula the Uterus!

2. 2UTERINE CYCLE OverviewMENSTRUATION:- BREAKDOWN OF THE UTERINE ENDOMETRIUM AND VAGINAL BLEEDING DUE TO LOW ESTROGEN AND PROGESTRONE LEVELS.Menstrual days: 1-5PROLIFERATIVE PHASE:- GROWTH OF THE UTERINE ENDOMETRIUM UNDER ESTROGEN STIMULATION.Proliferative days: 6-14SECRETORY PHASE:- STIMULATION OF THE UTERINE GLANDS SECRETION BY PROGESTRONE.Secretory days: 15-27Ischemic days: 27-28

3. 3THE FEMALE HORMONESHYPOTHALAMUS:- GONADOTROPIN RELEASING HORMONE [GnRH].PITUITARY:-LUTEINIZING HORMONE [LH] FOLLICLE STIMULATING HORMONE [FSH] PROLACTIN [PRL]OVARY:-DEVELOPING FOLLICLE:- ESTROGEN.CORPUS LUTEUM:- PROGESTRONE.

4. 4THE FEMALE HORMONES FUNCTIONSFOLLICLE STIMULATING HORMONE [FSH] STIMULATE FOLLICULAR DEVELOPMENT, MATURATION & ESTROGEN SECRETION.LUTEINIZING HORMONE [LH] STIMULATE THE CORPUS LUTEUM FORMATION AND PROGESTRONE SECRETION.PROLACTIN [PRL] STIMULATE BREAST ALVEOLI MILK PRODUCTION.

5. 5ESTROGEN FUNCTIONSGROWTH & DEVELOPMENT OF FEMALE REPRODUCTIVE ORGANS.DEVELOPMENT OF FEMALE SECONDARY SEXUAL CHARACTERISTICS.GROWTH OF UTERINE ENDOMETRIUM.GROWTH OF THE BREAST DUCT SYSTEM.

6. 6PROGESTRONE FUNCTIONSSTIMULATION OF UTERINE GLANDS SECRETION.GROWTH OF THE BREAST ALVEOLI.INHIBITION OF UTERINE MUSCLES CONTRACTIONS DURING PREGNANCY TO PREVENT EXPULSION OF THE FETUS

7. 7THE MENSTRUAL CYCLES

8. HORMONAL REGULATION IN NONPREGNANT FEMALE(UTERINE CYCLE)HYPOTHALAMUS RELEASES GONADOTROPIN-RELEASING HORMONE (GnRH). This stimulates the anterior pituitary to release FSH and LH.

9. HORMONAL REGULATION IN NONPREGNANT FEMALE(UTERINE CYCLE)FSH STIMULATES MATURATION OF PRIMARY OOCYTE IN AN IMMATURE FOLLICLE.

10. HORMONAL REGULATION IN NONPREGNANT FEMALE(UTERINE CYCLE)FOLLICLE PRODUCES ESTROGEN. Estrogen: (A) builds the uterine wall (the endometrium); (B) inhibits secretion of FSH.

11. HORMONAL REGULATION IN NONPREGNANT FEMALEHIGH LEVELS OF ESTROGEN FURTHER STIMULATE SECRETION OF LH BY ANTERIOR PITUITARY. This plus FSH also causes ovulation of the secondary oocyte – leaving follicle without egg (the corpus luteum). (Approximately day 15.)

12. HORMONAL REGULATION IN NONPREGNANT FEMALE(UTERINE CYCLE)CORPUS LUTEUM SECRETES ESTROGEN AND PROGESTERONE. This maintains the endometrium for 15-16 days and inhibits LH.

13. HORMONAL REGULATION IN NONPREGNANT FEMALE(UTERINE CYCLE)(If oocyte is not fertilized and implanted in the uterine wall) CORPUS DEGENERATES (TO CORPUS ALBICANS) AND STOPS PRODUCING ESTROGEN AND PROGESTERONE.

14. HORMONAL REGULATION IN NONPREGNANT FEMALE(UTERINE CYCLE)WITHOUT ESTROGEN AND PROGESTERONE, ENDOMETRIUM BREAKS DOWN – MENSTRUATION OCCURS. Menstruation is the sloughing off of the enlarged endometrial wall along with blood and mucous.

15. HORMONAL REGULATION IN NONPREGNANT FEMALE(UTERINE CYCLE)DECREASE IN PROGESTERONE AND LH. Low LH causes secretion of FSH by pituitary again. The cycle repeats.

16. HORMONAL REGULATION IN NONPREGNANT FEMALE(UTERINE CYCLE)IF – SOMEWHERE BETWEEN:CORPUS LUTEUM SECRETES ESTROGEN AND PROGESTERONE. This maintains the endometrium for 15-16 days and inhibits LH.And (If oocyte is not fertilized and implanted in the uterine wall) CORPUS DEGENERATES (TO CORPUS ALBICANS) AND STOPS PRODUCING ESTROGEN AND PROGESTERONE.SPERM GETS TO EGG...FERTILIZATION CAN TAKE PLACE, AND ULTIMATELY, EMBRYO CAN BECOME IMPLANTED IN UTERINE WALL.