Hypothalamic-Pituitary Relationship 2

Question 1

Layers of Adrenal Glands and What Each Layer produces

Answer 1

Salt, Sugar, Sex
Zona Glomerulosa-Mineralocorticoid
-aldosterone

Zona Fasciculata-Glucocorticoids
-cortisol

Zona Reticularis-Sex hormones
-androgens

Medulla
-NorE

Question 2

Circadian Rhythm of Cortisol

Answer 2

Highest at 8am when you wake up and lowest at night, midnight?, when you sleep

Question 3

Regulation and Function of Aldosterone

Answer 3

Aldosterone works when BP is low
-detects Na in serum

Adrenal cortex works w angiotensin to cause absorption of Water/Na to increase BP

Question 4

What does Low Dose Dexamthasone Suppression Test tell you?

Answer 4

If you have Cushing Syndrome or not

-no ACTH suppression indicates CS

Question 5

What does a high dose Dexamethasone suppression test tell you?

Answer 5

If the cause is in the pituitary or not

• if ACTH is low, then you know the feedback went to pituitary and decreased it, so it has to be Cushing Disease
• if ACTH stays high, then you know ectopic

Question 6

How do you distinguish between Cushing caused by adrenal tumor vs pituitary tumor?

Answer 6

If only Cortisol is high, but ACTH and CRH are low, then it is an Adrenal tumor

If both ACTH and Cortisol high, then pituitary tumor

Question 7

How does aldosterone cause sodium reabsorption

Answer 7

Aldosterone causes the formation of a protein channel that pumps Na+ into the blood, while K+ is pumped out into lumen

Question 8

What is the precursor for ACTH?

Answer 8

Pro-opiomelanocortin

Question 9

Why does increased ACTH cause hyperpigmentation?

Answer 9

ACTH also causes the formation of melanin

Seen in Addison’s disease

Question 10

Cosyntropin Stimulation Test for Adrenal Gland Insufficiency

Answer 10

If at 8am,

-lower than 3 ug/dL=AI
-3-15, give cosyntropin, and if <18ug/dL then AI confirmed, measure ACTH
—low/normal=2 or 3
—elevated=1

Question 11

1 adrenal insufficiency

Answer 11

Elevated ACTH, low cortisol, and low aldosterone due to no adrenal cortex

-can also see elevated Renin

Question 12

2 adrenal insufficiency

Answer 12

Low ACTH, low cortisol, but normal aldosterone

Question 13

Primary Adrenal Excess

Answer 13

Elevated cortisol, but low CRH and ACTH

Question 14

Secondary pituitary excess

Answer 14

High cortisol, high ACTH, low CRH and see hyperpigmentation

Question 15

Hyperaldosteronism-1 vs 2

Answer 15

1-Conn’s Syndrome=excessive aldosterone from adenoma in adrenal cortex

2=excessive release of renin from kidney

Question 16

17a Deficiency

Answer 16

Going to knock out cortisol and androgens, but have aldosterone

So see high BP, with lack of sexual development

Question 17

21B Deficiency

Disorders

Answer 17

Going to knock out aldosterone and cortisol, but not androgens

So low BP with increased secondary sex characteristics
-salt wasting

Question 18

11B deficiency Disorder

Answer 18

Going to knock out aldosterone and cortisol, but still have androgens

Still have DOC (mild mineralcorticoid), so will have elevated BP with increased secondary sex characteristics

Question 19

How do you tell the difference between a 21B and 11B disorder?

Answer 19

11B still has high BP due to DOC, even without the aldosterone

Question 20

Pheochromocytoma

Answer 20

Rare, benign tumor that secretes too much Catecholamines

Very dangerous

Question 21

Synthesis of NorE

Answer 21

Tyrosine to L-dopa to dopamine (RLS is tyrosine hydroxylase)
-shuttled through VMAT1 into granule, where converted to NorE

From here, shuttled back out through VMAT 1 to make Epi using PNMT, where it is shuttled again back into chromaffrin granule

Question 22

What does it mean if COMT and MOA are increased?

Answer 22

Likelihood that Catecholamines are increased!

Question 23

Where are the important receptors for Catecholamines found?

Answer 23

B1-heart; increase contraction

B2-lungs; dilation of lungs