Menstrual cycle regulation

Hormonal role in menstrual cycle

1. MENSTRUAL CYCLE REGULATION Misbah Akram

2. Menstruation??? Natural changes that occur in the uterus and ovary as an essential part of making sexual reproduction possible. Essential for the production of eggs, and for the preparation of the uterus for pregnancy.

3. Average length= 28 days Ages of 11 and 14 Controlled by hormones Interaction between hypothalamus, pituitary, ovaries & uterus. Each cycle divided into phases

4. Each female reproductive cycle has two components: Ovarian cycle Uterine cycle

5. Ovarian Cycle Ovulation occurs at 14 th day of 28-days ovarian cycle. 14 days prior to ovulation are called follicular phase. While 14 days after ovulation constitute luteal phase.

6. Uterine Cycle Ovulation occurs at 14 th day of 28-days uterine cycle. 14 days prior to ovulation are subdivided into menstrual phase (day 1-5) and a proliferative phase (6 -14) . While 14 days after ovulation constitute secretory phase.

7. In the first 5 days, GnRH stimulates anterior pituitary to increase production of FSH and LH. Day 1-5: Primordial follicle matures to primary follicles each containing a diploid primary oocyte. Day 6-13: Primary follicles form secondary follicles. After 16 hours: FSH & LH Maturation of follicle called graafian follicle. Just prior to ovulation, primary oocyte complets meiosis 1 to form secondary haploid oocyte. Follicular Phase

8. Ovulation Release of secondary oocyte from mature follicle. Guided by high level of LH. Luteal Phase Days: 15-28 Remaining ovarian follicular cells form a yellowish structure called corpus luteum. Production of progesterone and estrogen by corpus luteum

9. Menstrual Phase Progesterone Shedding of endometrial lining. Woman’s period. Proliferative Phase Estrogen produced by follicular cells endometrian begins to reform

10. Secretory Phase Days: 15-28 Progesterone and estrogen from corpus luteum stimulates further thickening of the endometrium. In case of no fertilization: Corpus luteum becomes corpus albicans. Decreased level of progesterone and estrogen Leads to menstruation.

11. HORMONES ARE

12. *Gonadotropin-releasing hormone Five hormones involved in an elaborate scheme involving both positive and negative feedback

13. ROLE of GnRH IN THE MENSTRUAL CYCLE The hypothalamus secretes GnRH in a pulsatile fashion GnRH activity is first evident at puberty Follicular phase GnRH pulses occur hourly Luteal phase GnRH pulses occur every 90 minutes Loss of pulsatility down regulation of pituitary receptors   secretion of gonadotropins Release of GnRH is modulated by – ve feedback by: steroids gonadotropins Release of GnRH is modulated by external neural signals

14. High levels of estrogens suppress the release of GnRH (bar) providing a negative-feedback control of hormone levels.  Secretion of GnRH depends on certain neurons in the hypothalamus which express a gene (KISS-1) encoding a protein of 145 amino acids. From this are cut several short peptides collectively called  kisspeptin . These are secreted and bind to  G-protein-coupled receptors  on the surface of the GnRH neurons stimulating them to release GnRH . However, high levels of estrogen inhibit the secretion of kisspeptin and suppress further production of those hormones.

15. Hormonal feedback control of menstrual cycle

16. Hormones of Placenta The placenta forms large quantities of human chorionic gonadotropin, estrogen, progesterone and human chorionic somatomammotropin , which are all essential to a normal pregnancy HUMAN CHORIONIC GONADOTROPIN (HCG) HCG is a glycoprotein with a molecular weight of 39,000. It is secreted by the syncytial trophoblast cells and can be measured in the blood 8 to 9 days after ovulation. The rate of secretion rises rapidly to reach maximum bout 10 to 12 weeks after ovulation and decreases to much lower value by 16 to 20 weeks after ovulation. It continues at this level for the remainder of pregnancy.

17. This hormone is identical to LH in its effect and therefore is able to maintain the corpus luteum past the time when it would otherwise regress. The secretion of estradiol and progesterone is thus maintained and menstruation is normally prevented . Diagnosis of the early pregnancy

18. MENSTRUAL DISEASES DYSMENORRHEA (PAINFUL CRAMPS) MENORRHAGIA AMENORRHEA/OLIGOMENORRHEA PREMENSTRUAL SYNDROME

19. UTERINE FIBROIDS ENDOMETRIOSIS POLYCYSTIC OVARIAN SYNDROME  DYSFUNCTIONAL UTERINE BLEEDING (DUB)

20. OTHER RISK FACTORS INCLUDE: Weight . Smoking and Alcohol Use . Stress . Menstrual Cycles and Flow . Chronic Pelvic Pain Diet Too much exercise POSSIBLE COMPLICATIONS anemia osteoporosis infertility quality of life

21. DIAGNOSIS first the patient history blood and hormonal tests ultrasound OTHER DIAGNOSTIC PROCEDURES Hysteroscopy Laparoscopy Endometrial Biopsy Dilation and Curettage (D&C) MEDICATIONS Nonsteroidal Anti-inflammatory Drugs (NSAIDs) levonorgestrol , drospirenone , norgestrol , norethindrone , and desogestrel . PROGESTINS Gonadotropin releasing hormone ( GnRH ) agonists