Lec 21 Reproductive III Flashcards
What is role of leptin in puberty?
increased fat tissue –> increased leptin –> triggers puberty
What is role of kisspeptin in puberty?
agonist for GPR54 receptor in brain; may initiate pulsatile GnRH secretion
What is effect of FSH in puberty?
FSH increases E2 levels
What happens in female puberty?
- growth spurt [androgens and E2] before menarche
- breast budding stimulated by ovarian E2
- pubic hair stimulated by adrenal and ovarian androgens
- uterus elongates and ovaries enlarge
When is normal menarche?
age 12-16 yrs (avg 12.5)
When is first day of bleeding in menstrual cycle?
day 1
What is follicular phase? How long?
period from onset of menses to ovulation
variable duration avg 14 days
What is luteal phase? duration?
period from ovulation to onset of bleeding
constant length of 14 days
When is estradiol highest in menstrual cycle?
at time of ovulation
When is progesterone highest in menstrual cycle?
after ovulation in luteal phase
What happens in follicular phase?
LH stimulates theca cells to produce androgens
androgens diffuse to granulosa cells and serve as substrate for E2 production
What is effect of LH surge in ovulation?
- stimulates completion of meiosis
- stimulates luteinization of granulosa cells
- stimulates progesterone production by corpus luteum
What is effect of progesterone rise in ovulation?
- causes synthesis of prostglandins in follicel necessary for ovulation
- enhances production of proteolytic enzymes for digestion and rupture of follicular wall
What is effect of FSH mid cycle surge prior to ovulation?
- induces production of plasmin
- frees oocytes from the follicle wall
- increases expression of LH receptors
What are clinical signs of ovulation?
- mittelschmerz [main from follicle rupture]
- ferning of cervical mucus
- increased spinnbarekit
- rise in basal body temp
- increased libido
What is most fertile time period?
the 1 or 2 days before ovulation
What is role of progesterone in luteal phase?
secreted by corpus luteum
corpus luteum is maintained by LH (hCG in pregnancy)
promotes secretory endometrium, edema, angiogenesis
What is luteolysis?
apoptosis of corpus luteum in luteal phase –> leads to progresterone decrease
What happens to E2 and P in luteal phase?
abrupt decrease in E2/P
local secretion of prostaglandins –> vasospasm and ischemic necrosis –> menstrual bleeding
prostaglandins induce uterine contractions
What is PMS?
complex of symptoms at end of luteal phase only in ovulating women; remission within 3 days after onset of menses