Question

MCAT Tutorial: The Female Hormone Cycle

Answer 1

\({\bf{Overview:}}\)
- three main cycles to consider:
the gonadotropic cycle (concerning the production of LH and FSH)
the ovarian cycle (concerning the release of an egg cell)
the endometrial cycle (concerning the thickening/thinning of the endometrial lining)



\({\bf{The~Gonadotropic~Cycle:}}\)
- pituitary gland poduces lutenizing hormone and follicle stimulating hormone (LH and FSH)
- FSH promotes the egg to mature from the secondary oocyte & estrogen production.
- LH promotes ovulation and development of the corpus luteum
- production of both peaks at ~14 days and is low during the rest of the cycle.
- peak of cycle: the follicle releases the egg & ovulation occurs

Answer 2

\({\bf{Ovarian~Cycle:}}\)
- divided into the follicular phase (0-14 days) and luteal phase (14-28 days)
- follicular phase: estrogen & progesterone low
> estrogen peaks at about ~12-13 days. secreted to prepare for a potential pregnancy. estrogen also increases the production of LH. decreases but starts to increase production a bit at the 22-23 day mark before decreasing again if no conception
> progesterone peaks at about ~21 days. produced by corpus luteum. inhibits FSH.
- luteal phase: endometrial lining builds (see endometrial phase) in response to progesterone.

\({\bf{Endometrial~Cycle:}}\)
- releases lining during menstrual cycle
- starts rebuilding the lining at ~ 3 days
- divided into menstrual phase (when lining is shed), proliferative phase (~6-14 days, lining starts building up again) and secretory phase (~14-28 days, lining continues to grow until ~ the 28 day mark when it is shed again and re-enters the menstrual cycle)

Answer 3

Anyway, that's the end of my tutorial, I hope it was a helpful resource. Source material is the 2nd Edition Barron's Prep book for the new MCAT