Adrenal Gland

Question 1

Arteries and veins?

Answer 1

Right adrenal gland- lots of arteries and one vein draining into the inferior vena cava
Left adrenal gland- lots of arteries and one vein draining into the renal vein

Question 2

3 zones of the adrenal cortex and what they produce?

Answer 2

Zona glomerulosa- aldosterone
Zone fasciculata- cortisol, androgens, oestrogens
Zone reticularis- cortisol, androgens, oestrogens

Question 3

What does the adrenal medulla produce?

Answer 3

Catecholamines- adrenaline and noradrenaline

Question 4

How many carbons in cholesterol?

Answer 4

27

Question 5

Aldosterone mechanism of action?

Answer 5

Stimulates Na+ reabsorption by promoting production of Na+ ion channels in kidneys

Stimulates K+ and H+ secretion

Raises blood volume and pressure

Question 6

How is aldosterone regulated?

Answer 6

Decrease in renal blood pressure causes release of enzyme renin

Renin converts angiotensinogen from the liver into angiotensin 1

Angiotensin 1 converted into angiotensin II by ACE

Angiotensin 2 causes activation of enzymes 3BHSD and 21,11,18 hydroxylases to form aldosterone

Question 7

Effects of cortisol?

Answer 7

Increased metabolism, especially fat, and gluconeogenesis

Excretion of water

Question 8

How is cortisol regulated?

Answer 8

Negative feedback- cortisol inhibits CRH in hypothalamus and ACTH in pituitary gland

Question 9

Effects of ACTH on adrenals?

Answer 9

Activation of enzymes 3BHSD and 21,11 and 17 hydroxylases to produce cortisol

Question 10

Cortisol levels in the day?

Answer 10

Diurnal, lowest at night and highest in morning

Question 11

Addison’s disease causes?

Answer 11

Autoimmune disorder so adrenal cortex is degraded

Tuberculosis of adrenal cortex

Pituitary gland releases more ACTH and hence MSH

Question 12

Addison’s disease symptoms?

Answer 12

• Vitiligo
• Tanning (hyperpigmentation)
• Diarrhea, constipation
• Low blood pressure
• Weakness
• Weight loss

Question 13

Why do patients get tanned?

Answer 13

Pro-opio-melanocortin (POMC) protein converted into ACTH and MSH.

MSH pigments skin cells

Question 14

Addison’s disease treatment?

Answer 14

Saline

Dextrose to prevent hypoglycaemia due to glucocorticoid deficiency

Hydrocortisone or another glucocorticoid

Question 15

4 causes of Cushing’s syndrome?

Answer 15

Steroid usage

Pituitary dependent Cushing’s disease

Ectopic ACTH (lung cancer)

Adrenal adenoma or carcinoma

Question 16

Cushing’s syndrome symptoms?

Answer 16

Diabetes

High blood pressure

Weakness

Depression

Bruising

Thin skins

Moon face

Question 17

Cushing’s syndrome treatment?

Answer 17

Surgery or radiotherapy for tumour

Anti-cortisol and ACTH medications

Question 18

Catecholamine precursor molecules?

Answer 18

Tyrosine→ dopamine→ noradrenaline and then adrenaline

Question 19

Catecholamines stored and released in response to?

Answer 19

Stored in cytoplasmic granules and released in response to Ach from preganglionic sympathetic neurones

Question 20

Catecholamine roles?

Answer 20

‘Fight or flight’, tachycardia, sweating, glycolysis, gluconeogenesis, vasoconstriction

NA and Adr circulate bound to albumin

Question 21

Catecholamines degraded by which 2 enzymes?

Answer 21

Monoamine oxidase and catechol-O-methyl transferase