Female Reproductive Physiology - Meininger Flashcards
What causes the most change in steroid hormone production in girls?
Steroid hormone production results more from changes in the number or sensitivity of receptors on target cells than from changes in gonadotropin concentrations
What are the gonadotropins?
1) FSH
2) LH
What are the two modes of gonadotropin release?
1) tonic mode
2) surge mode
What is tonic mode?
1) similar to males
2) low but pulsatile release of LH
What is surge mode?
1) unique to females
2) periodic massive release of LH (ovulation)
Which set of ducts gives rise to the female reproductive system?
Mullerian ducts
What is the difference between male and female duct system development?
1) females duct system development is independent of gonadal hormones (no ovaries necessary)
2) males need testes for their development
Where are the sites of ovarian hormone production?
Ovarian follicles
What do the ovarian follicles contain?
1) oocyte
2) layers of supporting cells
3) proper hormonal environment
What kind of follicles are females born with and how do they progress?
1) born with primordial follicles
2) convert to primary follicles throughout life (independent of gonadotropins)
What step of prophase are primary oocytes arrested in until ovulation?
primary oocytes are arrested in prophase of meiosis I until ovulation
What arrests primary oocytes in Prophase of Meiosis I ?
Granulosa cell derived oocyte maturation inhibitor in the follicular fluid
What triggers the resumption of meiosis at ovulation?
LH via blockage of the inhibitor
The way gametes in the female develop…
episodically
How many follicles ovulate?
One
What happens to the follicles that are recruited but aren’t ovulated?
1) arrested in an immature state
2) undergo degeneration (atresia)
What proliferates early in the development of the follicle?
1) Granulosa cells
2) the acquire FSH receptors and produce estrogen in response to FSH
What are the steps in follicle development?
1) granulosa cell proliferation
2) further granulosa cell proliferation
3) accumulation of fluid within the follicle
4) formation of the antrum
5) ovulation - follicle ruptures and the ovum is released
6) remaining cells undergo luteinization and form the corpus luteum
What cells have FSH receptors?
Only granulosa cells
What are the main hormone products of the ovary and what produces them?
1) estradiol - by the follicle
2) progesterone - corpus luteum
What hormones are made in small amounts by the ovary?
1) androgens
a) DHEA
b) androstenedione
What hormones are made by the granulosa cells?
1) peptide hormones
a) inhibins
b) activins
2) released into follicular fluid and general circulation
Where else is inhibin made besides in granulosa cells?
1) corpus luteum
2) post ovulation
What hormones cause follicular develop after the antral phase?
FSH and LH