B8.027 Prework 3: Physiologic Changes in Menopause Flashcards
normal control of menstrual cycle
complex interplay of HPO axis
what leads to menopause transition
loss of ovarian follicles with aging
ultimately leads to cessation fo menses
describe the steps of the early transition of perimenopause
as the # of follicles decrease, inhibin decreases and E rise can be slower, which in turn can cause FSH to rise
ovulatory dysfunction can occur
higher FSH can sometimes recruit a second cohort of follicles which can transiently cause E2 levels to rise
-early ovulation can trigger cycle length to decrease
-luteal out of phase cycles (LOOP)
describe the steps of the late transition of perimenopause
decreasing follicles with decreasing E level
decreased ovulation
decreased P
lengthening of cycles and lighter bleeds
process of ovarian aging
ovaries shrink
number of follicles decreases substantially
production of inhibin and AMH decreases
remaining follicles respond poorly to elevated FSH and LH
result of ovarian aging
erratic ovulation with occasional double ovulation results in menstrual cycle irregularity and potentially high estradiol levels
changes in hypothalamus during menopause
decrease in estrogen leads to loss of inhibition of GnRH
amount of GnRH secreted with each pulse is increased, accompanied by a decrease in pulse frequency
**this may contribute to compromise or absence of the midcycle LH surge
role of AMH in menopause
correlated with ovarian reserve
can help predict age
serum hormone levels at menopause
decreased circulating estrogens decreased ratio of estrogen: androgen decreased SHBG secretion increased peripheral aromatization of DHEA to estrone reversal of estradiol to estrone ratio no change in T
function of estrogens
- stim secondary sex characteristics of females
- prepare uterus for sperm transport
- increase vascular permeability and tissue edema
- stimulate growth and activity of mammary glands and endometrium
- prepare endometrium for progestagen action
- mildly anabolic, stimulates calcification
- active during pregnancy
- regulate behavior and secretion of gonadotropins
estrogen predominance in reproductive years
estradiol (E2) from dominant follicle and CL
estrogen predominance in menopausal years
estrone (E1) from peripheral aromatization of adrenal androstenedione in adipose and stromal tissue
functions of progesterone
- prepare uterus to receive conceptus
- maintain uterus during pregnancy
- stimulate growth of mammary glands, but suppress secretion of milk
- general mild catabolic effect
- regulate secretion of gonadotropins
estrogen receptor activity
2 types: a and b
both are present in the ovary and the central nervous system, as well as many other tissues
complex effects throughout body (both beneficial and deleterious)
discuss how different compounds can induce different structural alterations within the estrogen receptors
so ya this happens
things can be pure antagonists, pure agonists, or mixed (SERMs)
