Neuroendocrine

Question 1

4 neurohormones of the hypothalamus, not including GnRH

Answer 1

TRH
CRH
GHRH
Dopamine(!)

Question 2

Where in the hypothalamus can you find the GnRH cell bodies?

Answer 2

The arcuate nucleus

Question 3

Where do GnRH cells originate from?

Answer 3

The olfactory area (hence why the x linked Kallman syndrome is a due to failure of GnRH migration

Question 4

When do primordial germ cells reach the genital ridge?

Answer 4

6 weeks

Question 5

Describe a primordial FOLLICLE (no germ cell)

Answer 5

Single layer of squamous like granulosa cells

Question 6

Describe a secondary follicle

Answer 6

Multiple layers of granulosa cells, with beginning of theca cell development

Question 7

What is characteristic on an antral follicle?

Answer 7

Accumulation of follicular fluid

Question 8

Where do male germ cells undergo spermatogenesis?

Answer 8

Seminiferous tubules

Question 9

Define spermatogenesis?

Answer 9

The process by which an immature diploid spermatogonium becomes an haploid spermatozoa

Question 10

Where do sertoli cells live?

Answer 10

They are secretory cells that line the seminiferous tubules

Question 11

What are the first signs of gonadotropin independent primordial follicle maturation?

Answer 11

-Granulosa cells become cuboidal
-Increase in oocyte size
-Gap junction development between oocyte and

Question 12

What happens to antral follicles that aren’t “rescued” by FSH

Answer 12

The undergo specifically, apoptosis, or programmed cell death

Question 13

How does actually FSH promote follicle growth?

Answer 13

FSH stimulates the aromatase activity in granulosa cells creating the estrogenic environment required for continued cell growth (an androgenic environment fosters cellular atresia)

Question 14

Besides size, how is the dominant follicle different then the other follicles?

Answer 14

More FSH receptors and more advanced microvasculature compared to the other follicles, allowing it to continue to grow

Question 15

When in the luteal phase do progesterone levels peak?

Answer 15

midluteal phase

Question 16

when are gonadotropins at their nadir?

Answer 16

Late luteal phase

Question 17

What part of the HPO axis does stress, weight loss, and eating disorders effect?

Answer 17

The hypothalamus, inhibiting GNRH neuronal activity, leading to dysfunctional gonadotropin secretion and anovulation (even though gonadotropin levels might be normal when checked.)

Question 18

What is the most common way that PCOS affects gonadotropin levels?

Answer 18

There is an INCREASE in serum LH due to increases in LH pulse frequency and amplitude, and normal to LOW concentrations of serum FSH. This causes disordered follicular development and ovarian hyperandogenism

Question 19

How does chronically elevated estrogen causes anovulation?

Answer 19

It inhibits FSH secretion necessary for follicular development, and then the poor follicular development doesn’t generate the estradiol levels necessary for the LH surge. (This is also why you dont get your period when your pregnant)

Question 20

Do you measure free or total T for PCOS?

Answer 20

Both. Total is the actual value, free is calculated

Question 21

Prometrium is what kind of progestin and what is the dose for women with POI?

Answer 21

Micronized progesterone. 200mg daily for 12 days a month

Question 22

What are the proteins produced by the liver that increase with estrogen?

Answer 22

thyroxine-binding globulin (TBG), corticosteroid-binding globulin (CBG), sex hormone-binding globulin (SHBG), triglycerides, high-density lipoprotein (HDL) cholesterol, and clotting factors

Question 23

Estrace is what type of estrogen?

Answer 23

micronized estradiol

Question 24

1mg of oral estradiol (estrace) is equivalent to what dose of oral conjugated estrogens (premarin)?

Answer 24

0.625mg conjugated estrogens

and 0.05mg transdermal estrogen

Question 25

What is considered a low dose ESTRADIOL patch (for HRT)?

Answer 25

0.014mg estradiol

Question 26

What does the National Academy of Clinical Biochemistry consider the upper limit of normal for TSH?

Answer 26

2.5mIU/L, because 95% of people without evidence of thyroid disease have a TSH <2.5. However if they lowered the upper limit from 4.5 to 2.5 then an additional 28 million people would be diagnosed with HypoT

Question 27

What is the ASRM’s 2015 statement on SCH (with TSH >2.5) and miscarriage?

Answer 27

There is FAIR evidence that SCH, defined
as a TSH level >4 mIU/L during pregnancy, is associated with
miscarriage, but insufficient evidence that TSH levels between
2.5 and 4 mIU/L are associated with miscarriage

Question 28

What composes a gonad

Answer 28

Germ cells AND somatic cells

Question 29

Where to primordial germ cells migraine from?

Answer 29

Hindgut/yolk sac where they originate to gonadal ridge, *Between 4-6 weeks

Question 30

What is the gene on SRY region of chromosome Y that determines a gonads becomes a testes?

Answer 30

TDF (testes determining factor)

Question 31

When do primordial germ cells differentiate into sertoli cells?

Answer 31

7 weeks. Sertoli cells +spermatogonia = testicular cords. Important because TCs produce AMH for mullerian regression, and ABP (androgen binding protein) to maintain high local adrogen environment for spermatogenesis

*Leydig cells differentiate at 8 weeks!

Question 32

The hormone produces by Leydig cells *starting at 8 weeks

Answer 32

Testosterone. Maintained by LH and maternal/placental HCG. Maternal HCG is why patients with Kallman syndrome still produce testosterone in utero and so have phenotypic appearance at birth

Question 33

What are the wolffian duct structures specifically

Answer 33

Epididymis, vas deferns, seminal vesicles * dependent on testosterone*
and
male external genitalia, urethra and prostate dependent on DHT

Question 34

Two genes necessary for ovarian developement

Answer 34

WNT-4, RSPO1- they suppress SOX9

Question 35

If the germ cells are undergoing mitosis for rapid aggregation of oogonia between 6-8 weeks, when do the oogonia undergo MEIOTIC division to become a primary oocyte arrested in prophase 1?

Answer 35

During the 11-12th week. Male spermatogonia do NOT undergo meiosis in utero

Question 36

In the neonate, how many oocytes have been lost since they reached there max at 20 weeks GA

Answer 36

80%! Now only 500,000-2 million by birth