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Question 1

Label each as a postive or negative regulator of GnRH release: dopamine, serotnin, B-endrophin, norepinephrin, and leptin.

Answer 1

Question 2

What are the two phases of the menstrual cycle and how long does each one usually last?

Answer 2

Each cycle lasts 28 [to 35] days with two phases -

follicular [proliferative]

luteal [secretory] of approximately 14 days each.

Question 3

Where does 95% of estrogen (estradiol) come from?

Answer 3

comes from ovaries

Question 4

How does the midcycle LH surge effect follicular cells?

Answer 4

It causes them to change their steroid production from estrogen to progesterone

Question 5

What exactly causes the switch in steroid production during the LH surge?

Answer 5

caused by increased expression of CYP11A1 and 3β-hydroxysteroid dehydrogenase conversion of cholesterol to progesterone.

Estrogen is decreased by downregulation of aromatase.

Question 6

Where do female androgens come from?

Answer 6

Female androgens come from adrenal glands, ovaries, and peripheral conversion of androstenedione and DHEA to testosterone

Question 7

How are females protected from virilization and conversion of testosterone to DHT?

Answer 7

by higher levels of SHBG

Question 8

What is Inhibin B and Inhibin A a marker of and what is each one controlled By?

Answer 8

Inhibin B

Marker of: Granulosa cell function

Regulated By FSH

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Inhibin A

Marker of: Corpus luteun function

Regulated By LH

Bc B is after A so ofc its going to be longer (FSH)

Question 9

What hormones regulate the follicular phase (day 5-13)?

Answer 9

FSH stimulates follicle recruitment and growth, and estrogen synthesis

Before selection of the follicle for ovulation, granulosa cells respond only to FSH.

As the follicle matures cAMP increases, upregulating LH receptors, allowing both LH and FSH stimulation of granulosa cells .

its called follicle stimulating hormone so it makes sense

Question 10

What causes ovulation of day 14?

Answer 10

LH surge