Repro Physiology Flashcards
The α subunit is similar in what 4 hormones, giving them abilities to stimulate some of each other’s hormonal properties?
β-hCG, TSH, FSH, & LH
Where is β-hCG produced?
A small amount may be produced by the anterior pituitary but the majority comes from the placenta
(thus any more than a minimal amount of β-hCG is indicative of pregnancy)
Where is Progesterone synthesized?
Ovarian tissues: including granulosa, theca and luteal cells
(in a process stimulated by LH and FSH)
In women, androgen is made where?
Androgen is made by follicular theca cells
& by luteinized theca cells
Do the ovaries produce glucocorticoids?
No.
The ovary does not have 21 deoxyhydrogenase or 11 beta dehydrogenase therefore cannot synthesize glucocorticoid or mineralocorticoids.
When is “day 1” of a woman’s menstrual cycle?
The first day she notices menstrual bleeding
Which menstrual phase dictates the length of the cycle? How long is it usually?
How does this change at menarche, reproductive age, perimenopausal, & menopausal ages?
Follicular phase, normally 10-14 days
Menarche: immature hypothalamus → irregular follicular development rates and irregular cycles
Reproductive age: predictable follicular development, predictable cycles
Perimenopausal: older eggs, longer follicular development, longer cycles
Menopausal: no eggs, no cycles
How do contraceptives affect a woman’s reproductive abilities after she stops using them?
They don’t affect this once they are stopped
Millions primordial follicles are developed in utero. They grow and undergo atresia regularly unless rescued by _____
FSH
however while using OCPs, they are not “saved” and will just become apoptotic & die
______ stimulates growth of granulosa & initiates steroid production.
FSH
The appearance of LH receptors on the theca cells is directed by _____
FSH
Blood vessels also appear in the ovary, as this vasculature is necessary to deliver _____-containing cholesterol which is the basis of steroid hormone
VLDL
What is an “Antral Follicle”
Mature or Graafian follicle
PCOS - pathophysiology?
- Androgens are produced in excess by the ovary
- High levels of androgens overwhelm the aromatase enzyme
• Instead of conversion to estrogen, androgens are converted to more potent androgens
– Cannot become estrogen
– Inhibit aromatase
– Inhibit LH receptor formation
High local androgen environment == multiple small follicles are present but unable to fully develop.
Thus: No ovulation
- Infertility, irregular menses
- Hirsuitism, acne
The negative feedback of __a__ on __b__ normally controls oocyte production to just one per cycle.
a) estrogen
b) FSH
When follicle has more __a__ than __b__, it is “selected” as the dominant follicle
a) estrogen
b) androgen
What happens during the early vs. late halves of the Follicular phase?
Early:
- FSH stimulates ↑Estrogen production & ↑LH receptors
- Dominant follicle established (day 5-7)
- Estrogen levels increase, causing ↓FSH, ↑LH, & ↑FSH receptors on local granulosa cells so they respond to the little FSH that remains
Late:
- LH → ↑Androgen production by theca cells
- Remaining FSH → Conversion of androgen to Estrogen in granulosa cells, maintaining estrogen-dominated environment
What is the meaning of “luteinized” & to what cells does this occur/apply?
What is the outcome/effect of this?
It refers to the appearance & function of granulosa cells once they begin to secrete Progesterone in response to stimulation by LH.
The remaining FSH and LH plus the newly produced progesterone stimulate the release of enzymes which digest through the follicular cells allowing release of the oocyte with a little cluster (“cumulus”) of attached granulosa cells. This is referred to as Ovulation.
The LH surge stimulates meiosis from what phase to what?
prophase I → metaphase II
What hormone does the corpus luteum produce?
Progesterone
How does the Progesterone-only pill work to produce contraception?
By inhibiting the LH surge & ovulation