Adrenal Physiology

Question 1

T/F adrenal cortex and medulla have separate embryological orgins

Answer 1

True, they just fuse during development

Question 2

What does the adrenal medulla secrete?

Answer 2

catecholamines and neurohormones

Question 3

T/F adrenal medulla is a true endocrine gland

Answer 3

False, it is a modified SNS ganglion

Question 4

What are the three zones of cortex?

Answer 4

zona reticularis
zona fasciculata
zona glomerulosa

Question 5

T/F Reticularis is the outer most layer of the adrenal gland

Answer 5

false, it’s the innermost layer of the cortex

Question 6

What the the zona reticularis secrete?

Answer 6

androgens, estrogens, DHEA

Question 7

Where are glucocorticoids secreted?

Answer 7

mostly in the fasciculata, but also in the reticularis

Question 8

What does the glomerulosa secrete?

Answer 8

mineralocorticoids, mostly aldosterone

Question 9

What is the function of aromatase?

Answer 9

make DHEA or estradoil from androgen or testosterone

Question 10

Which enzyme converts progesterone to cortisol and aldosterone

Answer 10

21-hydroxylase

Question 11

T/F Stress can increase cortisol secretion

Answer 11

true

Question 12

T/F We keep up a constant cortisol level at all time

Answer 12

False, the secretion follows circadian rhythm

Question 13

What are the functions of CRH?

Answer 13

signal ACTH release
effects on immune response 
inhibition of appetite 
signal onset of labor 
linked to mood disorders

Question 14

What is POMC?

Answer 14

the precursor protein of ACTH

Question 15

T/F Rise in ACTH gives rise to more a-MSH

Answer 15

True, ACTH undergoes proteolysis to make a-MSH

Question 16

What are the functions of cortisol?

Answer 16

stimulate energy catabolism
permissive for glucagon and catecholamine actions
suppress immune system
negative Ca balance

Question 17

Why do we need to taper the doses of cortisol when we want to get off the drug?

Answer 17

with long term use, adrenal gland will be desensitised, so we need to gradually build up the tolerance for atrophic cells

Question 18

What are the signs of excess cortisol

Answer 18

Cushing’s - weight gain, increased catabolism, weakness of muscle, immune suppression, effects on HPO and HPT axis

Question 19

Which cell in the adrenal medulla secrete neurohormones

Answer 19

chromaffin cells