Adrenal Disorders (9)

Question 1

What is adrenal failure known as (cortisol deficiency)

Answer 1

Addison’s disease

Question 2

What is excess cortisol (adrenal overactivity) known as

Answer 2

Cushing’s disease

Question 3

Describe the anatomy of the adrenal gland

Answer 3

Left adrenal vein drains into the left renal vein and then into the inferior vena cava (indirect since via renal vein). Right adrenal vein drains directly into the inferior vena cava

Question 4

What do both adrenal glands have

Answer 4

many arteries but both have only one central vein

Question 5

why is it necessary to vaccine against HIB and pneumovax before elective left adrenalectomy

Answer 5

it can be easily damaged during a left adrenalectomy because it is right next to the left adrenal gland

Question 6

What is cortisol controlled by

Answer 6

ACTH which turns on the correct enzymes to make cortisol.

Question 7

what is the hypothalamo pituitary adrenal gland

Answer 7

The hypothalamus releases CRH. The corticotrophs in the anterior pituitary gland release ACTH/Corticotrophin. The adrenal gland releases cortisol

Question 8

how can pregnenolone be turned into mineralcorticoids (aldosterone) and glucocorticoids (cortisol) ?

Answer 8

it is oxidised and hydroxylated

Question 9

what is the difference between aldosterone and cortisol

Answer 9

the position of the OH group is different

Question 10

How are enzymes that act on cholesterol body labelled

Answer 10

by the number of the carbon that they affect

Question 11

How are enzymes that act on cholesterol body labelled

Answer 11

by the number of the carbon that they affect

Question 12

What is POMC/Proopiomelanocortin

Answer 12

A precursor for ACTH. POMC is cleaved into smaller peptides including ACTH, MSH and endorphins. An increase in MSH leads to darkened skin, therefore people who have pathological levels of ACTH may become inappropriately tanned

Question 13

What is Addison’s Disease caused by

Answer 13

Can be caused by autoimmune disease where the immune system wipes out the adrenal cortex - Autoimmune vitiligo (antibodies against the skin cause patches of depigmentation) (commonest in the UK) Also tuberculosis of the adrenal glands (commonest WORLDWIDE).

Question 14

What is addisons disease

Answer 14

Primary adrenal failure. Because the adrenal glands are failing the pituitary secretes more ACTH in order to try and make the adrenal glands produce more cortisol. POMC is a precursor to ACTH as well as MSH, so if ACTH levels are high than so too are MSH which means that the skin can darken.

Question 15

What are the features of Addisons disease

Answer 15

Increased pigmentation. Autoimmune vitiligo may coexist. The lack of cortisol and aldosterone leads to salt loss, reduces the blood pressure, therefore eventual death from hypotension may occur.

Question 16

What is an Addisonian crisis and how is it treated

Answer 16

A crisis can occur because of severe hypotension resulting from lack of aldosterone and cortisol. If left untreated collapse and death will occur. To treat: 1. Rehydrate with normal saline, 2. Give dextrose to prevent hypoglycaemia, 3. Give hydrocortisone (synthetic cortisol) or other glucocorticoid.

Question 17

What are the biological actions of excess cortisol

Answer 17

Impaired glucose tolerance (diabetes). Weight gain (increase fat, lose protein). Thin skin and easy bruising.
Striae (stretch marks). Proximal Myopathy (weakness of the large muscles). Mental changes (depression). Hypertension. Fat Redistribution. Moon Face. Interscapular Fat Pad (‘buffalo pad’). Hirsuitism (facial hair) and acne.

Question 18

What are the four causes of Cushing’s Syndrome

Answer 18

Taking steroids by mouth. Piuitary adenoma producing excess ACTH - this is Cushing’s disease. Ectopic ACTH - some lung cancer cells can start to produce ACTH (if you remove the tissue, Cushing’s syndrome disappears). Adrenal adenoma (tumour of adrenal glands)

Question 19

Clinical Signs of Cushing’s Syndrome

Answer 19

Thin skin. Proximal myopathy. Centripetal obesity (lemon on sticks). Diabetes, hypertension and osteoporosis. Immunosuppression (reactivation of TB). Moon face

Question 20

Cushing’s syndrome vs Cushing’s disease

Answer 20

Cushing’s syndrome is where the cause is unknown, but clinical features observed. A high serum cortisol and low ACTH points to this. Cushing’s disease is where cause is determined to be pituitary adenoma and a high serum cortisol and a detectable ACTH points to this.

Question 21

what are the features of cushings syndrome the same as

Answer 21

the side effects of steroids

Question 22

What is Conns syndrome

Answer 22

Aldosterone Producing Adenoma. Its a tumour of the zona glomerulosa (which produces aldosterone). Aldosterone makes you retain sodium and lose potassium. Features are hypertension, oedema and low blood potassium