3. Female Endocrinology Flashcards
hypothalamus action
secretes gonadotrophin releasing hormone to act on anterior pituitary gland
anterior pituitary gland action
responds to GnRH from hypothalamus
secretes FSH and LH
what is the effect of FSH?
causes ovaries to secrete oestrogens (most common = oestradiol)
what is the effect of LH?
causes ovaries to secrete progesterone - important in pregnancy
effect of oestrogen AND progesterone
feed back to anterior pituitary and hypothalamus to inhibit GnRH secretion
when do oestrogen levels decrease?
menopause ~52 yrs
increased oestrogen causes
long bone growth female psyche (more caring) fair complexion breast development widening of pelvis maturation of genitalia female pattern pubic hair subcutaneous fat deposition ovulation and menstruation
what is different about GnRH secretion in females?
hypothalamus is pulsatile - determines whether FSH or LH is secreted
hormonal progression through menstrual cycle
FSH secretion increases
oestrogen secretion increases
this causes FSH secretions to dip
reduction in FSH causes reduced oestrogen secretions
day 12: LH surge
causes increased progesterone and oestrogen secretion for ~7 days
FSH effect on ovarian follicle
causes follicle maturation
LH effect on ovarian follicle
causes ovum to be expelled 2 days after surge
oestrogen effect on cervix
dilates cervix
causes mucus plug to become highly viscous
progesterone effect on cervix
closes cervix
causes mucus plug to become thick, so bacteria/sperm cannot enter
oestrogen effect on endometrium
causes growth and thickening
progesterone effect on endometrium
endometrium enters secretory phase - secrets nutrients
