1.2 Reproductive Hormones Flashcards
components of a neuroendocrine reflex arc
stimulus > sensory neurons > transmission > efferent neuron > hypothalamus > neurohormone > blood > target tissue > response by target tissue
what pattern are reproductive hormones generally secreted in?
-pulsatile
- secreted periodically (female), in regular cycles, or constitutively (male).
what do “releasing hormones” do?
control the release of other hormones/factors
what do gonadotropic hormones do?
stimulate gonads
biochemical hormone classsification
-peptides
-steroids
-fatty acid derivatives
gonadal steroid synthetic pathway
cholesterol > pregnenolone > progesteron > testosterone > estradiol
fate of steroid hormones after secretion
secretion by gonad > enters blood, moves to target tissue > causes change in target tissue > passes through liver > liver renders steroid water soluble > reenters blood, enters kidney or bile > excreted in urine or feces
which part of the hypothalamus is sensitive to positive feedback? what would happen here if estradiol levels increased?
surge centre
-estradiol up > increase GnRH from hypothalamus > increase LH from pituitary > increased stimulation of terminal follicular development, ovulation, and early CL
what part of the hypothalamus responds with negative feedback? what would happen here if progesterone and estradiol levels increased?
increased progesterone + estradiol > decreased GnRH from hypothalamus > decreased LH from pituitary > ovulation blocked
what does LH do in the Theca cells? What does FSH do in granulosa cells?
LH acts on Theca cell - cholesterol > androgen
FSH acts on granulosa cell - androgen > estrogen
GnRH - biological classification, source, male target tissue, female target tissue, male primary action, female primary action
Biochem Classification - releasing factor, gonadotropin?
source - hypothalamus
Male target tissue - anterior pituitary lobe (ALP)
female target tissue - ALP
male primary action - release of FSH and LH from ALP
female primary action - Release of FSH and LH from ALP
LH - biological classification, source, male target tissue, female target tissue, male primary action, female primary action
Biochem Classification - glycoprotein
source - anterior pituitary
Male target tissue - Testis (interstitial cells of Leydig)
female target tissue - Ovary (theca interna and luteal cells)
male primary action - stimulates testosterone production
female primary action - Stimulates ovulation, CL formation and progesterone secretion
FSH - biological classification, source, male target tissue, female target tissue, male primary action, female primary action
Biochem Classification - protein
source - anterior pituitary
Male target tissue - Testis (sertoli cells)
female target tissue - Ovary (theca interna and luteal cells)
male primary action - stimulates testosterone production
female primary action - Stimulates ovulation, CL formation and progesterone secretion
Prolactin - biological classification, source, male target tissue, female target tissue, male primary action, female primary action
Biochem Classification - protein
source - anterior pituitary
Male target tissue - Testis and brain
female target tissue - mammary cells, CL in some species
male primary action - can induce maternal behaviour in males and females
female primary action - lactation, maternal behaviour
oxytocin - biological classification, source, male target tissue, female target tissue, male primary action, female primary action
Biochem Classification - peptide
source - Synthesized in hypothalamus, stored in PLP, also synthesized by CL
Male target tissue - smooth muscles of epididymis
female target tissue - Myometrium and endometrium of uterus, mammary gland
male primary action - pre-ejaculatory movement of spermatozoa
female primary action - uterine motility and milk ejection; luteolysis
E2 - biological classification, source, male target tissue, female target tissue, male primary action, female primary action
Biochem Classification - steroid
source - granulosa cells of follicles, placenta, sertoli cells of testis
Male target tissue - brain, inhibits long bone growth
female target tissue - hypothalamus, entire repro tract and mammary gland
male primary action - sexual behaviour, sperm production and epididymis function
female primary action - sexual behaviour, elevates secretory activities of the entire repro tract, elevates uterine motility
P4 - biological classification, source, male target tissue, female target tissue, male primary action, female primary action
Biochem Classification - steroid
source - corpus luteum and placenta, adrenal gland?
Male target tissue - ?
female target tissue - uterine myometrium, endometrium, mammary gland
male primary action - ?
female primary action - maintenance of pregnancy
T - biological classification, source, male target tissue, female target tissue, male primary action, female primary action
Biochem Classification - steroid
source - leydig cells (male), theca iinterna cells (female)
Male target tissue - accessory sex glands
female target tissue - brain, ganulosa cells
male primary action - anabolic growth, spermatogenesis, secretion of accessory glands
female primary action - substitute for estradiol, synthesis, abnormal sex characteristics
inhibin - biological classification, source, male target tissue, female target tissue, male primary action, female primary action
Biochem Classification - glycoprotein
source - granulosa cells (female), sertoli cell (male)
Male target tissue - ALP
female target tissue - ALP, ovary
male primary action - inhibits FSH secretion
female primary action - inhibits FSH secretion
inhibin - biological classification, source, male target tissue, female target tissue, male primary action, female primary action
Biochem Classification - glycoprotein
source - granulosa cells (female), sertoli cell (male)
Male target tissue - ALP
female target tissue - ALP
male primary action - stimulates FSH secretion
female primary action - stimulates FSH secretion
PgE2 - biological classification, source, male target tissue, female target tissue, male primary action, female primary action
Biochem Classification - prostoglandin
source - ovary, uterus, embryonic membranes
Male target tissue - ?
female target tissue - CL, oviduct
male primary action - ?
female primary action - ovulation, stimulates progesterone production from CL
PgF2a - biological classification, source, male target tissue, female target tissue, male primary action, female primary action
Biochem Classification - prostaglandin
source - uterus, vesicular glands
Male target tissue - epididymis
female target tissue - CL, uterus, ovarian follicles
male primary action - affects metabolic activity of sperm
female primary action - ovulation, luteolysis
Equine chorionic gonadotropin (eCG) - biological classification, source, male target tissue, female target tissue, male primary action, female primary action
Biochem Classification - glycoprotein
source - chorionic girdle cells
Male target tissue - NA
female target tissue - ovary
male primary action -
female primary action - causes formation of corpus lutea
Human chorionic gonadotropin (hCG) - biological classification, source, male target tissue, female target tissue, male primary action, female primary action
Biochem Classification - glycoprotein
source - trophoblast of blastocyst
Male target tissue - NA
female target tissue - ovary
male primary action - increase growth of fetal testis
female primary action - facilitate production of progesterone by ovary
