WH Physiology Flashcards
What is the function of E2 in the follicular phase of the menstrual cycle?
Build up the endometrium
What secretes estrogen in the follicular phase of the menstrual cycle and how does this relate to the HPO axis?
The strongest primordial follicle will secrete massive E2. This follicle is surrounded by granulosa cells (bind FSH and LH) and theca cells (bind LH) which work together to make E2.
What days of the cycle are in the follicular phase?
Day 1-12; the first 7 are menses
What binds to theca cells and why do we care?
Theca cells have LHr’s that result in cholesterol –> progesterone –> androgens
What binds to granulosa cells and why do we care?
Granulosa cells can bind LH and FSH. FSH triggers aromatase conversion of androgens (produced in theca cells) to estrogens.
Explain the HPO axis in the follicular phase
GnRH is triggered by increasing E2 that’s being released by various primary follicles = increases FSH/LH = increases E2 production at the follicle with the most receptors!
What days are ovulation and what happens at this time?
Days 12-14 of the cycle. The extremely high amounts of E2 released by the primordial/graffian follicle leads to the paradoxical SURGE of LH and FSH (mostly LH) and thus release of the oocyte.
Menstruation is
the first 7 days of the follicular phase that consists of endometrial sloughing due to the CL deteriorating from no hCG and thus no more E2/progesterone.
What is the luteal phase and when in the cycle does it occur?
Luteal phase is 14-28 which consists of the CL secreting mostly progesterone along with E2. These FB to the pituitary to shut off FSH/LH release.
Define menopause.
12 months or more of amenorrhea at the average age of 51 y/o caused by estrogen deficiency
