206/207 - Endocrine Control of Female Reproduction I & II Flashcards Preview

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Flashcards in 206/207 - Endocrine Control of Female Reproduction I & II Deck (40)
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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




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?




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



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?



Secondary amenorrhea = used to have normal menstruation, but it stopped


Before treating a patient with PCOS, what diagnostic evaluation must be done?

Rule out other causes of high androgens

  • Very high testosterone => Testosterone-secreting tumor
  • High DHEAs => adrenal source
  • High 17-OH-progesterone => Congenital adrenal hyperplasia
  • Elevated free cortisol in urine => Cushing syndrome



How is hypothalamic amenorrhea treated?

  • To relieve symptoms (ex: low bone mineral density)
    • Hormone replacement
  • To induce fertility
    • Injectable gonadotropins
    • Pulsatile GnRH

Also, behavioral therapy


Note: Leptin is NOT currently a therapeutic option


Which gonadotropins are favored by the following GnRH secretion patterns?

  • High frequency:
  • Low frequency:
  • Continuous:

  • High frequency: LH secretion
  • Low frequency: FSH secretion
  • Continuous: No secretion
    • Desensitization inhibits both LH and FSH 



Why is it important to treat patients with PCOS, even if they don't want to become pregnant and are unbothered by hirsutism and/or acne?

PCOS = unopposed estrogen

-> incresed risk of endometrial cancer


  • Must induce ovulation (or theoretically give periodic progesterone?) to protect the endometrium


Will people with PCOS have a positve or negative progestin challenge?


  • Estrogen is present, but abnromalities in hormone signaling prevent progesterone production, LH surge



Which hormone suppresses prolactin?


  • Dopamine tonically inhibits prolactin release


Decreased dopamine -> increased prolactin


What does a positive progestin challenge imply about the cause of a patient's secondary amenorreha?

Implies normal outflow tract, adequate estrogen

=> Cause of amenorreha is not enough progesterone to induce ovulation


Progestin challenge mimics little rise in progesterone before ovulation


How is menopause diagnosed?

(lab test, assuming consistent clinical picture)

High FSH 

  • Due to lack of inhibin, lack of estrogen negative feedback


List 2 causes of hypothalamic amenorreha

  • Genetic defect: Kallman syndrome
    • GnRH neurons fail to igrate
    • -> Primary amenorrhea
  • Functional hypothalamic amenorrhea
    • May cause primary or secondary amenorrhea
    • Usually associated with increased stress
      (Nutritional, environmental, behavioral)



Why are estrogen-progestin challenges rarely done?

We can pretty easily measure estrogen levels in the blood


If normal and no bleed after progestin challenge, implies abnormal outflow tract


How does prolactin affect ovulation?

How is this adaptive (evolutionarily)?

Prolactin inhibits ovulation

  • Prolactin suppresses GnRH pulses
  • -> No LH/FSH
  • -> No positive feedback loop from estrogen
  • -> No ovulation 


Prolactin triggers lactation - adaptive to not be able to have another bably while breastfeeding a new one


What causes polyglandular autoimmune disease?


Auto-antibodies to endocrine organs

Can target ovaries -> premature ovarian failure


What is the most common cause of anovulation in teh setting of normal estrogen?



  • Ovary is "stuck" in the follicular phase
  • Theca cells are making andorgens, but granulosa cannot keep up with aromatization
    • High estrogen AND androgens, but androgens interfere with signaling
    • Cannot select dominant follicle 




What defines menopause?

1 year has gone by since last menstrual period


Technically it's the last menstrual period, but hard to know if it *really* is the last one until a year has gone by