Reproductive endocrinology Flashcards
GnRH source, target tissue, primary action
Source: hypothalamus
Target: anterior pituitary lobe
Action: Release of FSH and LH
LH source, target tissue, primary action
Source: Anterior pituitary lobe
Target tissue: testis (Leydig) or ovary
Action:
male - testosterone production
female - ovulation, formation of corpus luteum, progesterone secretion
FSH source, target tissue, primary action
source: anterior pituitary lobe
target: testis (sertoli) or ovary
action:
male - sertoli cell function
female - follicular development and estradiol synthesis
Prolactin source, target, primary action
Source: Anterior pituitary lobe
Target: Mammary cells, (males: testis and brain)
Action: lactation, maternal behavior
Oxytocin source, target, primary action
Source: posterior pituitary lobe, corpus luteum
Target: mammary gland and uterus
Action: uterine contraction, milk ejection
Estradiol source, target, primary action
Source: ovaries, placenta, testis
Target: brain, reproductive tract, mammary gland
Action: sexual behavior, uterine contraction
Progesterone source, target, primary action
Source: corpus luteum and placenta
Target: uterus, mammary gland, brain
Action: maintenance of pregnancy, inhibits reproductive behavior
Testosterone source, target, action
Source: Testes (leydig), ovaries
Target: Accessory sex glands, muscles, testes
Action: growth, spermatogenesis, secretion of accessory glands
Inhibin source, target, action
Source: testes (sertoli), ovaries
Target: gonads, pituitary
Action: Inhibits FSH
Relaxin source, target, action
Source: Corpus luteum, placenta, prostate
Target: Pelvic ligaments, cervix, mammary gland, nipples
How does female puberty start?
Oestradiol has a negative feedback on hypothalamus and GnRH release.
Before puberty the tonic center of hypothalamus has a high sensitivity to oestradiol –> only low levels of GnRH.
At some point negative feedback sensitivity decreases –> high amounts of GnRH –> puberty
Hormonally, what happens in anestrus?
There is insufficient GnRH release and therefore not enough sex hormones
