female germ cells
oocytes
remain in prophase of meiosis
theca cells
synthesize progesterone
theca w/ granulosa cells
synthesize estradiol
child hood hormone levels
FSH > LH
puberty hormone levels
LH > FSH
GnRH, FSH, & LH INCREASE & PULSATE
2 functions of ovaries
- oogenesis
- hormones (estrogen & progesterone)
functional unit of ovaries
single ovarian follicle
roles of fully developed ovarian follicle
- provide nutrients for oocyte
- ovulation
- prep vagina & fallopian tubes for fertilization
- prep uterus for implantation
- maintain hormone production for fetus
action of estrogen on target tissue
- mature & maintain of uterus, fallopian tubes, cervix, & vagina
- up-regulation of estrogen, progesterone & LH receptors
- Negative & positive feedback on FSH and LH secretion
- Lowering uterine threshold to contractile stimuli
action of progesterone on target tissue
- maintain secretion activity of uterus during luteal phase
- negative feedback on FSH and LH
- Raising uterine threshold to contractile stimuli during pregnancy
Follicular Phase
day 0-14
estrogen levels start to increases
receptors for FSH & LH are up-regulated (theca & granulosa)
FSH > LH
Negative feedback to stop FSH & LH by anterior pituitary
Ovulation
14 days before menses
burst of estrogen secretion
positive feedback causes ovulation
LH > FSH
estrogen levels decease after ovulation
Luteal Phase
Day 14-28
corpus luteum develops & makes progesterone and estrogen
Progesterone is prepping body for fertilized egg
basal temp rises
Menses Phase
regression of corpus luteum & abrupt loss of estradiol and progesterone
Hormone combinations of hormonal contraceptions
estrogen & progesterone
OR
progesterone only
feedback that occurs with hormonal contraception
negative feedback
inhibit FSH and LH - prevent ovulation
How does hormonal contraception reduce fertility?
hostile cervical mucus
decreased motility of the fallopian tubes
Menopause effects on estrogen
DECREASE levels of estrogen –> DECREASE negative feedback –> INCREASE secretion and pulsing FSH and LH
what are symptoms of menopause caused by
loss of ovarian source of estrogen
symptom of menopause
accelerated bone loss and vascular instability “hot flashes”
who is less symptomatic to menopause and why?
obese women b/c estrogen can be produced from androgenic precursors in adipose tissue
