206, 207 Female Endo

Question 1

Where are GnRH neurons located?

Answer 1

arcuate nucleus of the medial basal hypothalamus

Question 2

Where are LH and FSH secreted?

Answer 2

anterior pituitary gonadotrophs

Question 3

What hormones does LH stimulate in the ovary?

Answer 3

androstenedione and testosterone in theca cells

also stimulates progesterone in the corpus luteum (post-ovulation) and inhibin A production

Question 4

What hormones does FSH stimualte in the ovary?

Answer 4

regulates E2 production by stimulating granulosa cell growth and aromatase activity

stimulates inhibin B production

Question 5

How does the uterine lining change in response to estrogen and progesterone?

Answer 5

sheds in response to withdrawal of estrogen and progesterone (menses)

regenerates in response to estrogen

Question 6

Which tissues have aromatase activity?

Answer 6

granulosa cells, adipose tissue, breast, and CNS

Question 7

Hepatic SHBG production is increased by ___________ and decreased by ___________.

Answer 7

Hepatic SHBG production is increased by estrogen and thyroid hormone and decreased by androgens, obesity, and insulin.

Question 8

What is the function of inhibin A in the ovary? Inhibin B?

Answer 8

Inhibin A: secreted in granulosa/theca cells of the dominant follicle and the corpus luteum

Inhibin B: secreted by granulosa cells of small antral follicles, increases in response to FSH stimulation

Question 9

What is the function of activin?

Answer 9

stimulates FSH release, often bound to follistatin (inhibitor)

Question 10

What is the funciton of follistatin?

Answer 10

inhibits activin, inhibits follicular growth

Question 11

Fast GnRH pulse frequency selectively increases ______ release; slow GnRH pulse frequency selectively increases ______ release.

Answer 11

Fast GnRH pulse frequency selectively increases LH release; slow GnRH pulse frequency selectively increases FSH release.

Question 12

What is the function of positive E2 feedback on the ovary/follicle?

Answer 12

positive E2 feedback triggers the LH surge and ovulation

Question 13

What is menarche vs. adrenarche?

Answer 13

adrenarche is the development of pubic and axillary hair (uncoupled from gonadarche)

menarche is the development of menstruation

adrenarche occurs between age 6-8 (before puberty), menarche occurs at around age 12-13 (after breast budding)

Question 14

What are the major milestones of early follicular phase?

Answer 14

FSH remains high

dominant follicle selected

LH pulse frequency increases, stimulates theca cell T production (leading to FSH induced conversion to E2 in granulosa cells)

inhibin B increases follicular growth

Question 15

What are the major milestones of mid follicular phase?

Answer 15

increasing GnRH pulse frequency + increasing E2/inhibin B = suppressed FSH release

Question 16

What are the major milestones of late follicular phase?

Answer 16

increased E2 production triggers LH surge –> induces ovulation of dominant follicle

Question 17

What are the major milestones of the luteal phase?

Answer 17

post ovulatory follicle forms corpus luteum and secretes progesterone and E2 (slows GnRH pulse frequency –> increased FSH, decreased LH)

increased FSH stimulates follicle recruitment for the next cycle

if no conception, the corpus luteum dies and progesterone is not produced (leading to menses)

Question 18

What is the difference between estrogen and progesterone action on endometrium?

Answer 18

estrogen: proliferation of stromal and epithelial cells, increased progesterone receptors
progesterone: induces differentiation of proliferative endometrium, prepares endometrium for embryo

Question 19

What is primary vs. secondary amenorrhea?

Answer 19

primary = no menarche by 15-16 yo (evaluate if no secondary sex characteristics by age 13)

secondary = no menses for 6 months

Question 20

How is anovulation diagnosed?

Answer 20

appropriately timed P and LH measurements or a lack of increase in basal body temperature

Question 21

What is hypogonadotropic hypogonadism in women?

Answer 21

anovulation, oligomenorrhea, or amenorrhea with low or inappropriately normal LH/FSH levels

Question 22

What are some common causes of functional hypothalamic amenorrhea?

Answer 22

weight loss (ex. eating disorder)

exercise

stress

Question 23

What are the hormonal changes in chronic hyperandrogenic anovulation?

Answer 23

increased frequency of GnRH pulsing leading to increased LH/decreased FSH

leads to theca cell overproduction of androgens and underconversion to estrogen (because of decreased FSH)

Question 24

What is the assessed with progestin and estrogen challenges?

Answer 24

assesses if source of bleeding is related to androgen insufficiency, estrogen insufficiency, both, or neither

bleeding after progestin = evaluate for secondary amenorrhea

no bleeding after progestin, bleeding after estrogen = hypothalamic amenorrhea or ovarian failure

no bleeding after either = consider anatomic abnormality

Question 25

What are the symptoms of hyperprolactinemia in women?

Answer 25

galactorrhea (milky discharge)

infertility

menstrual disturbances

hypogonadism (symptoms of low estrogen)

Question 26

What is Asherman’s syndrome?

Answer 26

an outflow tract abnormality of the uterus with multiple intrauterine synechiae, which can be due to infection, surgery, D&C, etc.