206/207 - Endocrine Control of Female Reproduction I & II Flashcards
When during the menstrual cycle does progesterone peak?
7 days after ovulation
(When the corpus luteum is chugging along making progesterone)
How will levels of the following hormones change in ovarian failure?
- Estradiol:
- LH/FSH:
- Estradiol: low
- LH/FSH: high
Vs. hypothalamic amenorrhea, will have low estradiol AND low LH/FSH
Which ovarian cells aromatize androgen to estrogen?
Which gonadotropin stimulates the development of these cells?
Granulosa cells
FSH
How will levels of the following hormones change in hypothalamic amenorrhea?
- Estradiol:
- LH/FSH:
- Estradiol: low
- LH/FSH: low
Vs. ovarian failure, will have low estradiol and HIGH LH/FSH
How is PCOS diagnosed?
Requires 2/3 of:
- Oligo and/or anovulation
- Signs of hyperandrogenism
- Ultrasound with ≥12 2-9 mm follicles in each ovary OR increased ovarian volume
- The immature follicles look like cysts
Note: criteria has historically been 12 follicles, but I think she mentioned that now with improved imaging techniques we can see follicles better so we may actually see a lot more, and if someone has 12 follicles but no sx of PCOS probably do not need to diangose
List the phase of follicular development and predominant hormone that loosly aligns with the following phases of the endometrial cycle:
- Menses:
- Proliferative phase:
- Transition between proliferative and secretory:
- Secretory phase
- Menses
- Follicular phase
- Low estradiol and progesterone
- Proliferative phase:
- Follicular phase
- High estrogen
- Transition between proliferative and secretory:
- Ovulation
- High estrogen, progesterone beginning to rise
- Secretory phase
- Luteal phase
- High progesterone, estrogen falls
List 3 things that increase levels of sex hormone binding globulin
- Hyperthyroidism
- Pregnancy
- Estrogen treatment (OCPs)
All will decrease the effect of sex hormones; bound to SHBG = not biologically active
Which gonadotropin supports the corpus luteum?
Which hormone is produced as a result?
LH
Progesterone
- Corpus luteum produces progesterone*
- Note: LH also stimulates theca cells to produce androgens*
Which ovarian cells secrete androgens?
Which gonadotropin stimulates these cells?
Theca cells
LH
Which hormone supports early pregnancy?
Progesterone from the corpus luteum
[hormone] stimulates proliferation of the uterine lining
[hormone] stimulates differentiation of the uterine lining
Estrogen stimulates proliferation of the uterine lining
Progesterone stimulates differentiation of the uterine lining
After ovulation, what happens to the granulosa cells and theca cells that are left in the follicle?
They re-organize to become luteal cells
- Angiogenesis! Blood supply needed for delivery of cholesterol precursors for steroid synthesis
- More smooth ER and mito!
This forms the corpus luteum -> progesterone production
List 2 causes of gonadal dysgenesis
Turner syndrome (45, XO)
Fragile X carrier
Swyer syndrome (46XY)
Thank you @Ben Gastevich!
Describe the positive feedback loop that triggers ovulation
- Sustained high estrogen + progesterone bump
- Beginning of progesterone rise increases the pituitary response
- -> LH surge
- Normally, LH is inhibited by increased estrogen/progesterone
- -> Ovulation!
How does hypothyroidism affect menstruation?
(Describe the pathway)
Hypothyroidism = low thyroid horomone
- -> Upregualted TRH secretion from hypothalamus
- -> High TRH increases TSH and prolactin secretion
- Prolactin inhibits GnRH pulses
- -> No FSH/LH
- -> No ovulation
- -> No menstrual cycles
What is the most common cause of secondary amenorrhea?
Pregnancy
Secondary amenorrhea = used to have normal menstruation, but it stopped