Female Reproductive Physiology

Question 1

Functions of ovaries

Answer 1

oogenesis

secretion of sex hormones

Question 2

three zones of ovary

Answer 2

1. cortex – outermost, largest, contains oocytes
2. medulla
3. hilum – blood vessels and lymph

Question 3

functional unit of ovary

Answer 3

ovarian follicle

Question 4

functions of follicle

Answer 4

1. provide nutrients for oocyte
2. release oocyte at ovulation
3. prepare vagina and fallopian tubes for fertilization
4. prepare lining of uterus for fertilization
5. maintain hormone production

Question 5

when does meiosis begin in follicles? when does it end?

Answer 5

begins at gestational wk 20

ends 6 mo after birth

Question 6

sequence of oogenesis

Answer 6

primordial follicle –> primary follicle –> secondary follicle –> Graffian follicle –> ovulation

Question 7

what happens during first stage of oogenesis?

Answer 7

prophase of oocytes for 13-50 yrs
primordial follicle becomes primary follicle
theca interna cells develop
granulosa cells secrete fluid

Question 8

what happens during second stage of oogenesis?

Answer 8

70-85 days, only during reproductive yrs
granulosa and theca cells grow
follicle becomes Graffian follice
FSH accumulates in antrum

Question 9

what happens during third stage of oogenesis?

Answer 9

5-7 days after menses
single Graffian follicle achieves dominance, ruptures and releases oocyte –> becomes secondary oocyte and enters fallopian tube
remnants of ruptured follicle becomes corpus luteum and secretes hormones (regresses w/o pregnancy and becomes corpus albicans)
other follicles regress

Question 10

what is produced in the theca cells?

Answer 10

progesterone

androstenedione

Question 11

what is produced in the granulosa cells?

Answer 11

testosterone (converted from androstenedione via 17B-hydroxysteroid dehydrogenase)
17B-estradiol (converted from testosterone via aromatase)
inhibin (inhibits FSH secretion)
activin (stimulates FSH secretion)

Question 12

activity of GnRH

Answer 12

pulsatile activity

delivered to anterior pituitary –> stimulates pulsatile release of FSH and LH

Question 13

activity of FSH

Answer 13

stimulated by GnRH –> released from anterior pituitary
stimulates granulosa cells to produce estradiol (via activation of aromatase)
induces hypertrophy/hyperplasia of granulosa cells

Question 14

activity of LH

Answer 14

surges at midpoint of cycle –> ovulation

stimulates formation of corpus luteum and maintains its hormone production (via activation of cholesterol desmolase)

Question 15

feedback during menstrual cycle

Answer 15

follicular phase – FSH and LH stimulate estradiol production –> estradiol inhibits FSH and LH
midcycle – estradiol gets so large it induces FSH and LH (via upregulation of GnRH receptors)
luteal phase – progesterone inhibits FSH and LH

Question 16

actions of estrogen

Answer 16

maturation of repro tract
secondary sexual characteristic development
proliferation of granulosa cells
upregulation of estrogen, progesterone, and LH receptors
variable feedback on FSH/LH
maintenance of pregnancy 
excitement of uterine muscle
inhibition of prolactin activity
lowered LDL
closure of epiphyseal growth plates

Question 17

actions of progesterone

Answer 17

maintenance of uterus during luteal phase
negative feedback on FSH and LH
maintenance of pregnancy
thick, viscous cervical mucus
decreased excitement of uterine muscle
inhibits proliferation of vaginal epithelium
increases body temp during luteal phase