Adrenal Gland

Question 1

What makes up the adrenal gland

Answer 1

Two separate endocrine glands
Adrenal medulla
Adrenal cortex

Question 2

What is the adrenal medulla

Answer 2

Modified sympathetic ganglion derived from neural crest tissue
Chromaffin cells

Question 3

What does It release

Answer 3

Catecholamines direct into blood
Adrenaline
Noradrenaline
Dopamine

Question 4

What does the adrenal cortex release

Answer 4

Mineralcorticoid - aldosterone
Glucocorticoid - cortisol
Sex steroids

Question 5

What are very important hormones for the body’s survival

Answer 5

Aldosterone

Cortisol

Question 6

What zones make up the adrenal cortex and what do they secrete

Answer 6

Layers = GFR 
Zona glomerulosa (outer) = aldosterone
Zona fasiculata (middle) = glucocortico
Zona reticularis (inner) = sex

Question 7

What do glucocorticoids bind too

Answer 7

95% cortisol binding globulin

Only free can diffuse into cell

Question 8

How is cortisol essential for life

Answer 8

Cannot deal with stress i.e. maintaining glucose levels
Protects brain from hypo
Permissive to glucagon

Question 9

What is it stimulated by and how is this affected by certain things

Answer 9

Circadian rhythm - diurnal variation which peaks in morning and lowest in evening
- Possible why asthma worse in evening as less steroid for inflammation
Stimulated by stress similar to ACTH which release in pulses
Alcohol / caffeine / lack of sleep disinhibit the HPA affecting

Question 10

What has longer half life cortisol or ACTH

Answer 10

Cortisol

Question 11

What are the actions of cortisol on glucose metabolism

Answer 11

Acts to increase glucose
Gluconeogensis
Proteolysis to make glucose substrates for liver
Lipolysis
Decreased insulin sensitivity of muscle and adipose
Excess = type II DM

Question 12

What are additional actions of cortisol

Answer 12

Inhibits bone formation 
Decreased Ca absorption from gut and increased excretion at kidney
Increased bone resorption = osteoprosis
Increased metabolism 
Impaired mood and cognition 
Permissive to norepinerprine 
Suppress immune system

Question 13

How is it permissive to norepinephrine

Answer 13

A receptors cause vasoconstriction

Cushings = hypertension

Question 14

What does aldosterone do

Answer 14

Acts on distal tubule of kidney to increase reabsorption of Na and H20 and secretion of K
Causes increased blood volume and pressure

Question 15

What controls aldosterone

Answer 15

RAAS - renin angiotensin activating system

Question 16

How is renin activated

Answer 16

JG in afferent arteriole of kidney detects low BP e.g. if low BP due to stenosis
Secretes renin

Question 17

What does renin do

Answer 17

Converts angiotensingen in liver to ANG I

Ang 1 then converted to And 2 by ACE in the lungs

Question 18

What does Angiotensin II cause

Answer 18

Contriction to increase BP

Release of aldosterone from adrenal gland

Question 19

How do you differentiate between primary and secondary aldosteronism

Answer 19

Renin levels
If primary = low
If secondary e.g. renal artery stenosis = high as decreased perfusion stimulates JG cells to produce

Question 20

What does adrenaline do

Answer 20

Amine acting on alpha and beta adrenergic receptor 
Responsible fight or flight
Vasodilation - B2
Increases CO
Increases TPR
Vasoconstriction of skin and kidney

Question 21

What is endocrine action

Answer 21

Inhibits insulin and stimulate glucagon
Stimulates gluconeogenesis and glycolysis
Stimulates lipolysis
Stimulates ACTH