Endo week 4

Question 1

what kind of cells of the anterior pituitary are acidophilic?

Answer 1

what kind of cells of the anterior pituitary are acidophilic?

Answer:
Somatotropes and lactotropes

Question 2

what kind of cells of the anterior pituitary are basophilic?

hint: C.T.G

Answer 2

what kind of cells of the anterior pituitary are basophilic?

Answer:

• Corticotrophs
• Thyrotrophs
• Gonadotrophs.

Question 3

GH and Prolactin are what kind of hormones?

Answer 3

GH and Prolactin are what kind of hormones?

Answer:
protein hormones.

Question 4

LH, FSH, and TSH have what in common?

Answer 4

LH, FSH, and TSH have what in common?

Answer:
they are al glycoproteins and have the same alpha subunit (they differ in the beta subunit, which confer hormone specificity)

Question 5

somatostatin inhibits the secretion of which hormones?

Answer 5

somatostatin inhibits the secretion of which hormones?

Answer:

• GH
• TSH
• Prolactin(its not confirmed but it seems like to inhibit this)

Question 6

ACTH binds to which receptors in the adrenal cortex?

Answer 6

ACTH binds to which receptors in the adrenal cortex?

Answer: MC2R

(if it binds to MC1R it causes hyperpigmentation because it trigger melanin production)

Question 7

what are the functions/actions of TSH

hint: it does 6 things

Answer 7

what are the functions/actions of TSH

Answer:

• increase iodide pump activity (increase uptake of iodide)
• increase iodination of tyrosine to make TH
• increase release of TH in blood
• increase thyroglobulin (TH binding protein)
• increase size & secretory activity of thyroid cells.
• increase number of thyroid cells (hyperplasia)

Question 8

GnRH is released in ________ manner.

Answer 8

GnRH is released in ___pulsatile___ manner.

Question 9

Is prolactin synthesis stimulated by Estrogen?

Answer 9

Is prolactin synthesis stimulated by Estrogen?

Answer: Yes

Question 10

why does high levels of prolactin cause Amenorrhea, glactorrhea, and menstrual irregularities?

Answer 10

why does high levels of prolactin cause Amenorrhea, glactorrhea, and menstrual irregularities?

Answer:
- high levels of prolactin inhibit GnRH which is the regulator hormone for FSH and LH secretion. Normally, a surge in LH causes ovulation.
If PRL inhibit GnRH, then no LH will be secreted and no ovulation will happen.

• prolactin stimulates breast development & milk synthesis.

Question 11

what is the impact of hyperprolactinemia in males?

Answer 11

what is the impact of hyperprolactinemia in males?

Answer:

• Decreased libido (sex drive)
• Impotence (Erectile disfunction)
• Infertility

Question 12

Human chorionic Gonadotropin (hCG) is what and when is it produced?

Answer 12

Human chorionic Gonadotropin (hCG) is what and when is it produced?

Answer:
it is a glycoprotein similar to LH that is made when women are pregnant (egg is fertilized)

pregnancy test, test for the presence of hCG in urine.

Question 13

what things increases prolactin secretion (not tumours)

what things inhibit prolactin secretion

Answer 13

what increase prolactin secretion? 
pregnancy
exercise
stress (low stress, in high stress cortisol suppress PRL)
TRH
breast feeding
sleep
Estrogen

what inhibit/decreases prolactin secretion
Dopamine
GABA

Question 14

what is the most common cause of high serum prolactin?

how is this treated?

Answer 14

what is the most common cause of high serum prolactin?
- Lactotroph adenoma

how is this treated?
- dopamine agonist cabergoine (first-line of treatment)

Question 15

what is the mechanism of action of ACTH, TSH, LH, PRL

Answer 15

what is the mechanism of action of ACTH, TSH, LH, PRL

ACTH: cAMP
TSH: cAMP
LH: cAMP
PRL: tyrosine kinase (JAK-STAT)

Question 16

explain how a deficient thyroid gland can lead to amenorrhea.

Answer 16

explain how a deficient thyroid gland can lead to amenorrhea.

Answer:
if thyroid gland is deficient, no T3 & T4 will be made. Therefore, there will be no negative feedback mechanism, thus more TSH (from Anterior Pituitary) and TRH (from hypothalamus) will be secreted. As a results, TRH will stimulate lactotrophs to secrete more Prolactin (that normal amount of dopamine will not be able to inhibit). Prolactin inhibits GnRH, which responsible for secreting LH and FSH. Since there is no secretion of LH, and hence no spike, ovulation does not happen. This is amenorrhea.

Question 17

octreotides is analogues to which hormone?

Answer 17

octreotides is analogues to which hormone?

Answer: somatostatin

Question 18

Hormone prolactin has a short half life because it is not having a plasma binding protein

A. True
b. False

Answer 18

Hormone prolactin has a short half life because it is not having a plasma binding protein

Answer (i think) -> True

Question 19

Somatotropic tumors and prolactin secreting tumors are acidophilic in nature

A. True
B. False

Answer 19

Somatotropic tumors and prolactin secreting tumors are acidophilic in nature

True

Question 20

TWO hormones from the anterior pituitary influence milk production – True or False?

Answer 20

TWO hormones from the anterior pituitary influence milk production – True or False?

Answer: (i think) -> False [only prolactin synthesizes milk]

Question 21

The hormone MSH coming from POMC is for?

Answer 21

The hormone MSH coming from POMC is for?

Answer: skin colouring

Question 22

Which of the following clinical characteristics is common in women with hyperprolactinemia?

Answer 22

Which of the following clinical characteristics is common in women with hyperprolactinemia?

Answer: Menstrual irregularities

Question 23

Which two hormones are released when corticotrophs receive a signal by CRH?

A. ACTH and Prolactin
B. ACTH and Beta LPH
C. ACTH and TSH
D. ACTH and LH

Answer 23

Which two hormones are released when corticotrophs receive a signal by CRH?

Answer: B. ACTH and Beta LPH