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IN THE NAME OF GOD

IN THE NAME OF GOD. Female Horonal Cycle MENSTRUAL CYCLE E.Naghshineh MD. Reproductive hormons: GnRH. GnRH: decapeptide, by neurons in arcuate nucleus of hypothalamus Regulate secretion of two hormones: FSH and LH Pulsatile secretion Extremely short half-life: only 2-4 min.

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IN THE NAME OF GOD

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  1. IN THE NAME OF GOD

  2. Female Horonal CycleMENSTRUAL CYCLE E.Naghshineh MD

  3. Reproductive hormons: GnRH • GnRH: decapeptide, by neurons in arcuate nucleus of hypothalamus • Regulate secretion of two hormones: FSH and LH • Pulsatile secretion • Extremely short half-life: only 2-4 min

  4. Gonodotropins • LH &FSH: by ant pituitary gonadotroph cells • Ovarian follicular stimulation • Glycoproteins, alpha &beta subunit

  5. Prolactin • Poly peptide, by ant pituitary lactotroph • Primary trophic factor responsible for the synthesis of milk by breast • PRL secretion is under tonic inhibitory control by hypothalamic secretion of dopamine • PRL stimulation: breast manipulation, drugs, stress, exercise, certain foods

  6. TSH • By ant pituitary thyrotrophs in response to TRH • TRH:by arcuate nucleus ,portal circulation, pituitary • TRH: TSH & PRL release • Hypo- and hyperthyroidism: ovulatory dysfunction

  7. Oxytocin • 9 aa peptide, by paraventricular nucleus of hypothalamus • Uterine muscular contraction, breast lactiferous duct myoepithelial contraction

  8. MENSTRUAL CYCLE • Normal cycle length is considered 28 days • varies from female to female (21-35 days) • Ovarian cycle: 1-follicular ,2-luteal • Uterine cycle: 1-proliferative ,2-secreatory

  9. 1 – Follicular phase • Development dominant follicle, mature at midcycle, ovulation • Average length:10-14 days • Variability in length: variations in total cycle length

  10. 2-luteal phase • Ovulation to menses • Average length: 14 days

  11. Normal menstrual cycle • 21-35 days • 2-6 days of flow • Average blood loss:20-60 ml

  12. Hormonal variations • At the beginning of cycle: levels of gonadal steroids are low • Demise of corpus luteum, FSH levels rise, cohort of growing follicles is recruited, rise in estrogen: stimulus for uterine endometrial proliferation

  13. 3. Rising estrogen levels: negative feedback on pituitary FSH secretion; growing follicle produce inhibin-B: suppresses pituitary FSH secretion; Rising estrogen levels: LH initially decreases but late in follicular phase LH levels increased dramatically

  14. 4.At the end of follicular phase (just before ovulation) FSH-induced LH receptors on granulosa cells; with LH stimulation, modulate secretion of progesterone

  15. 7.Progesteron levels rise after ovulation; presumptive sign of ovulation 8.Progesteron;estrogen and inhibin-A : suppress gonadotropin secretion and new follicular growth

  16. 5.After sufficient degree of estrogenic stimulation; pituitary LH surge triggered, proximate cause of ovulation occurs 24 to 36 hours later

  17. 6.Estrogen level decreases through the early luteal phase from just before ovulation until midluteal phase, rise again as a result of corpus luteum secretion

  18. Cyclic changes of the Endometrium • Decidua functionalis: 2/3 superficial, proliferate and shed each cycle • Decidua basalis: deepest region, source of endometrial regeneration after each menses

  19. 1-Proliferative phase • First day of vaginal bleeding :day 1 of the menstrual cycle • Progressive mitotic growth of decidua functionalis, preparation for implantation of embryo • Thin endometrium (1-2 mm); straight, narrow, short endometrial glands become longer, tortuous structures

  20. 2-Secretory phase • 48 to 72 hours following ovulation, progesteron secretion: eosinophilic protein-rich secretory product in glandular lumen • Postovulatory day 6-7,maximal secretory activity: optimal for implantation of blastocyst • Stromal edema in late secretory phase

  21. 2 days before menses:dramatic increases in PMN migrate from vascular system

  22. Menses • Absence of implantations, glandular secretion ceases, irregular break-down of decidua fuctionalis • Destruction of corpus luteum and its productions estrogen and progesteron: cause of shedding • Withdrawal of sex steroids: spiral art spasm, endometrial ischemia, lysosoms breakdown, proteolytic enzymes release

  23. Ovarian follicular development • Fetus:6-7 million in 20 wks • At birth:1-2 million • At puberty:300,000 • Release during ovulation:400-500 • At menopause:rare

  24. Oogonia: only one final daughter cell (oocyte), three polar body • Oocyte arrested in prophase (diploten) until time of ovulation

  25. Two-cell two-gonadotropin theory: with LH stimulation, the ovarian theca cells produce androgens that convert by granulosa cells into estrogens under the stimulus of FSH

  26. THE END

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