47: HPA Axis: Adrenals

Question 1

What is ACTH derived from?

Answer 1

POMC

Question 2

What causes hyperpigmentation seen in Addison’s disease?

Answer 2

Excess ACTH -> increases melanin synthesis

Question 3

What does DHEAS stand for?

Answer 3

Dehydroepiandrosterone sulfate

Question 4

What is epi complexed with when stored in chromaffin granules?

Answer 4

ATP, Ca, chromogranins

Question 5

Chromogranins function

Answer 5

Decrease osmotic burden of storing E granules

Question 6

What does circulating chromogranins signal?

Answer 6

Sympathetic paraganglionic derived tumors

Question 7

What does cortisol upregulate in the adrenal medulla?

Answer 7

PNMT -> more epi produced from norep

Question 8

What does Ach do in adrenal medulla?

Answer 8

Stimulates synthesis of catecholamines

Question 9

Three things to measure in blood to determine total catecholamine production

Answer 9

1. Catecholamines
2. Metanephrines
3. Vanillylmandelic acid (VMA)

Question 10

Two enzymes that break down catecholamines

Answer 10

COMT, MAO

Question 11

which adrenergic receptors respond more to norep? Which one responds more to epi? Which responds equally?

Answer 11

Norep: A1, A2, B3
Epi: B2
Equal: B1

Question 12

A1 receptor function

Answer 12

Increase vascular smooth muscle contraction

Question 13

A2 receptor function

Answer 13

Inhibits norep and insulin release

Question 14

B3 receptor functions

Answer 14

Increase lipolysis, increase hepatic glucose output

Question 15

B2 receptor function

Answer 15

Increase glucose output from liver, vasodilation, work on bronchioles and uterus

Question 16

B1 receptor function

Answer 16

Increase cardiac output

Question 17

What causes pseudo-cushing’s syndrome?

Answer 17

Major depression and anxiety, acute/chronic illness, sometimes alcoholism

Question 18

How to detect adrenal insufficiency?

Answer 18

Cosyntropin (synthetic ACTH) stimulation test

Question 19

What causes Waterhouse-Friedrichsen syndrome?

Answer 19

N. Meningitidis or anticoagulants -> adrenal hemorrhage

Question 20

Axis that helps create aldosterone

Answer 20

Renin-angiotensin-aldosterone

Question 21

Treatment for primary and secondary adrenal insufficiency

Answer 21

Primary: replace cortisol and aldosterone
Secondary: replace cortisol