Recruitment of follicles to form primordial follicle is done by:
Ans: c (Follicle stimulating hormone) Ref: Shaw, 13th ed,p. 28Development of a primordial follicle into a graffian follicle is under the control of follicle stimulating hormone secreted by the anterior pituitary.FSH produces grow'th and development of ovarian follicles during the first 14 days after menses.This leads to gradual increase in estradiol production from granulosa cells of the ovary. This rise in estrogen suppresses FSF1 secretion initially (negative feedback).But then above a certain level, estradiol stimulates an increase in both the frequency and amplitude of GnRH pulses resulting in marked increase in LH secretion (positive feedback).i.e. minimum estradiol causes decrease in FSH high level of estradiol causes increase in LH secretionThis mid cycle peak of LH i.e.. LH surge induces ovulation. Thus in late proliferative phase of menstrual cycle. LH surge is triggered by an estradiol peak which exerts a positive feedback on LH secretion.Exogenously administered estrogen causes negative feedback on LH secretion.ProgesteroneIt maintains the uterus in quiescent stage during pregnancy by relaxing the myometrium.Corpus luteum is the major source of progesterone during first 10 week of gestation.After 12 weeks placenta is the major source of production of progesterone.The major substrate for progesterone is maternal cholesterol.Plasma progesterone level rises during pregnancy till term and falls rapidly after delivery, undetectable after 24 hrs post partum.Fetal synthesis contributes little to maternal level, therefore progesterone level will remain high even after fetal demise.Note:Corpus luteum is maintained by - lutenizing hormoneFern pattern is due to - estrogenAria- Stella reaction in ectopic pregnancy is due to - progesterone
Estrogen
HCG
Follicle stimulating hormone
LH
Endocrine Control of the Menstrual Cycle