Pituitary Hormone Function (GH/PRL) Flashcards Preview

DEMS EXAM 4 > Pituitary Hormone Function (GH/PRL) > Flashcards

Flashcards in Pituitary Hormone Function (GH/PRL) Deck (17)
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1
Q

Growth hormone is produced by ______________.

A

the somatotrophs of the anterior pituitary

2
Q

Growth hormone binds to what kind of receptor?

A

A cytokine receptor family

3
Q

What does growth hormone do?

A

Increases gluconeogenesis

Acts a counterregulatory hormone for insulin

Stimulates release of fatty acids by activating hormone-sensitive lipase

Stimulates amino acid uptake into muscle

4
Q

Growth hormone also causes the release of ______________.

A

insulin-like growth factor (IGF)

5
Q

The hypothalamus sends opposing signals to the pituitary in terms of GH release: _______________.

A

GHRH stimulates the release of GH and somatostatin (SST) inhibits it

6
Q

How does growth hormone affect the levels of GHRH and SST?

A

It inhibits the release of GHRH and stimulates the release of SST.

7
Q

GH inhibits the hypothalamic release of GHRH. What stimulates the hypothalamic release of GHRH?

A

Hypoglycemia and increased amino acids (arginine, specifically) in the serum

8
Q

Why are high levels of growth hormone fatal?

A

Because soft tissue responds to this, which cause cardiomegaly.

9
Q

Acromegaly results from excess ______________.

A

growth hormone after puberty

10
Q

Why does placental lactogen cause gestational diabetes?

A

Because it has a large homology to growth hormone

11
Q

Why is bromocriptine given to those with prolactinemia and neuroleptic malignant syndrome?

A

Because bromocriptine is a dopamine agonist

12
Q

What is unique about the regulation of prolactin?

A

The release of prolactin is tonically inhibited by the hypothalamus. Thus, if the hypothalamus is severed from the pituitary, then levels of prolactin will rise while other pituitary hormones will fall.

13
Q

What adenohypophyseal cells store GH?

A

Somatotrophs (GHRH and somatostatin)

14
Q

GH actions on IGF-1 work to _______________.

A

stimulate bone growth, muscle growth, and gluconeogenesis

15
Q

What adrenergic signals lead to increased release of GH?

A

Alpha-2 agonists or beta-antagonists

16
Q

Growth hormone binds to what kind of receptor?

A

JAK-STAT

17
Q

Two kinds of dwarfism result from defects in growth hormone. What are they?

A

Laron’s dwarfism: GH receptors

African pygmy syndrome: IGF receptors