Adrenal Glands And RAAS

Question 1

What are the zones of the cortex in order and what do they make

Answer 1

Zona glomerulosa (aldosterone)
Zona fasiculata (cortisol) so glucocorticoids
Zona reticularis (testosterone so androgens and some glucocorticoids)

Question 2

How would steroid hormones go into the cells

Answer 2

Attach to intracellular receptors (of the nuclear receptor family) - binding leads to the dissociation of the chaperones (heat shock proteins) - to the nucleus - binds to GREs (glucocorticoids receptor elements) and other transcription factors

Question 3

What is GRE

Answer 3

transcription factor
Glucocorticoid receptor element
Transcription can then occur

Question 4

Where does aldosterone act

Answer 4

In the distal tubule of the kidney
Would absorb NA+ and K+ so would allow more water to be taken up

Question 5

What happens in the RAAS system

Answer 5

Renin (kidneys juxtaglomular cells)
Ang (from liver) to ang 1
Ang 1 to Ang 2 by the ACE (in the lungs)
Stimulates the release of the aldosterone
Water uptake and would allow the increase in BP

Question 6

What else does ANG2 do

Answer 6

Stimulates the release of aldosterone
Allows vasoconstriction
Release of the ADH from the posterior pituitary

Question 7

What does cortisol do

Answer 7

Main stress hormone
Increased proteolysis
Increased lipolysis
More gluconeogenesis and glycogenlysis in the liver
BUT
low amino acid uptake
Low protein synthesis
Low glucose uptake

Question 8

When should the levels of Cortisol be measured

Answer 8

In the morning as that is when they peak

Question 9

What rhythm is ACTH released

Answer 9

Circadian rhythms
Short half life of 4-8 mins

Question 10

What are the other roles of cortisol

Answer 10

Anti-inflammatory
Immunosuppressive
Decreased osteoblast formation and so can lead to osteoporosis
CNS effects, neuronal death

Question 11

What are the weak androgens

Answer 11

DHEA
ANDROSTENEDIONE

Question 12

What are the Androgens regulated by

Answer 12

CRH and ACTH

Question 13

What is DHEA converted to and where

Answer 13

Testosterone in the testes

Question 14

Where is adrenaline made

Answer 14

In the chromaffin cells in the adrenal medulla

Question 15

What is the pathway of catecholamines made

Answer 15

Tyrosine
K(Tyrosine hydroxylase)
Levodopa
(Dopa decarboxylase)
Dopamine
(Dopamine beta hydroxylase)
Noradrenaline
(N-methyl transferase)
Adrenaline