Female Reproductive Function Flashcards
1
Q
ovarian cycle
A
- series of hormone mediated changes in the ovaries
- culminates in the monthly production of a viable ovum in women of reproductive age
- release ova and produce hormones
2
Q
follicular phase
A
- FSH stimulates development of follicles
- also rising estradiol
- estrogen is in a positive feedback loop that causes more FSH, which leads to true maturation of the follicle
3
Q
ovulatory phase
A
-LH surge causes rupture of Graafian follicle
4
Q
luteal phase
A
- LH converts the ruptured follicle to a corpus luteum
- progesterone (from corpus luteum) and some estradiol
5
Q
corpus luteum
A
-becomes corpus albicans if no fertilization
6
Q
primordial follicle
A
- increases in size during the ovarian cycle
- contains the ovum
- thecal and granulosa cells
- thecal cells feed granulosa cells and are vascularized
- granulosa cells produce estrogen
- other follicles regress
- the antrum has high levels of hormone that sustain the follicle
- graafian follicle gets to 20-33 mm
7
Q
uterine phases
A
- prepare uterus for implantation
- estrogen promotes proliferation of the endometrium and primes uterus for progesterone actions
- progesterone converts the proliferative uterus to a secretory uterus
8
Q
proliferative phase
A
- thickness of endometrium increases from 1-2 mm to 8-10
- comparable to the follicular phase
- dominated by estrogens and is variable in length
9
Q
secretory phase
A
- dominated by progesterone and has a fixed length of 14 days following ovulation
- progesterone promotes accumulation of glycogen, increased glandular secretions, and increased vascularity
- comparable to the luteal phase
10
Q
menstrual phase
A
- associated with prostaglandin mediated vasoconstriction of spiral arteries and local ischemic injury/ inflammation
- associated with the regression of the corpus luteum
11
Q
positive feedback
A
- in late follicular phase
- blood estradiol reaches a high level that initiates positive feedback and a surge in LH and FSH release, provoking ovulation
12
Q
negative feedback
A
- luteal phase
- estradiol, progesterone and inhibin produced by the corpus luteum have negative feedback on gonadotropin release
- no more FSH/LH- no ovulation again
- inhibin from granulosa cell
13
Q
LH
A
- secretion is pulsatile and increases in amplitude in the follicular phase
- high levels of estradiol (late follicular) enhance the sensitivity of the gonadotrophs to GnRH by increasing the number of receptors on gonadotrophs (ant pit)- surge in LH and FSH
14
Q
hypothalamic-pituitary-gonadal axis
A
- small bodied neurons in the arcuate nucleus and pre-optic are of the hypothal secrete GnRH
- increases secretion of FSH and LH
- FSH to granulosa cells-gene transcription and synthesis of relevant enzymes, activins and inhibins
- LH binds to receptors on ovarian thecal cells, stimulates biosynthesis of progestins and androgens
- androgens enter granulosa cells and are converted to estrogens
- granulosa cells also have LH receptors
15
Q
activins and inhibins
A
- negative feedback only on ant pit
- estogens and progestins on both