Diagnosing Adrenal Disorders

Question 1

Mineralocorticoids are produced in the

Answer 1

zona glomerulosa of the adrenal cortex

Question 2

Glucocorticoids (and some androgens) are produced in the

Answer 2

zona fasciuclata of the adrenal cortex

Question 3

Sex steroids, androgens (and some cortisol) are produced in the

Answer 3

zona reticularis of the adrenal cortex

Question 4

The adrenal cortex produces

Answer 4

glucocorticoids (cortisol), mineralocorticoids (aldosterone), sex steroids, and androgens

Question 5

The adrenal medulla produces

Answer 5

catecholamines - epinephrine and norepeinephrine

Question 6

Hydrocortisone

Answer 6

is the same as cortisol

Question 7

Cortisone

Answer 7

is a weak glucocorticoid metabolite of cortisol that is converted back to cortisol by the liver

Question 8

What are the actions of glucocorticoids?

Answer 8

Stimulation of gluconeogenesis (liver); mobilisation of amino acids (muscle); stimulation of lipolisis (adipose); immunosuppression

Question 9

What are the physiological consequences of too much cortisol?

Answer 9

Weight gain, wasting of muscle, skin, and bone, hyperglycaemia, hypertension (salt and water retention), and inhibition of linear growth if onset prior to puberty

Question 10

What are the two forms of hypercortisolism?

Answer 10

ACTH-dependent and ACTH-independent

Question 11

What are ACTH-dependent causes of hypercortisolism?

Answer 11

pituitary adenoma (Cushing’s disease); ectopic ACTH syndrome

Question 12

What are the ACTH-independent causes of hypercortisolism?

Answer 12

Cushing’s syndrome caused by adrenal adenoma or carcinoma, bilateral nodular hyperplasia of adrenals, or administration of x glucocorticoids

Question 13

What is the process of endocrine testing?

Answer 13

biochemical tests (x2) then radiology; measure specific hormones, their tropic (stimulating) hormone, and their regulated metabolite; stimulate or suppress if under/over active; 24hr urine

Question 14

What is the dexamethasone suppression test?

Answer 14

used in suspected Cushing’s; dexamethasone is a potent glucocorticoid which doesn’t measure in the cortisol assay - it will negatively feed back on pituitary to switch off cortisol production ie cortisol should go down in a normal person

Question 15

What are the physiological consequences of not enough cortisol?

Answer 15

GI symptoms (anorexia, nausea, vomiting, diarrhoea, weight loss), low BP (salt wasting), darkening of the skin (if ACTH secretion stimulated), muscle weakness (skeletal and cardiac), increased susceptibility to infection, and death

Question 16

What are the causes of Addison’s disease?

Answer 16

hypocortisolism due to genetic causes (enzyme defects in cortisol biosynthesis, metabolic defect/adrenoleukodystrophy), autoimmune adrenal destruction, infectious disease (eg TB)

Question 17

What are the physiological consequences of excess adrenal androgens?

Answer 17

If prior to puberty, premature pubic hair, hirsutism, acne, enlargement of penis or clitoris, behavioural changes, linear growth spurt, rapid epiphyseal fusion, muscular habitus, deepening of voice

Question 18

What are the clinical uses of glucocorticoids and adrenal steroids?

Answer 18

replacement of deficiencies caused by pituitary or adrenal disease (eg ACTH, cortisol); anti-inflammatory and immunosuppressive agents (ashtma, arthritis, skin rashes, autoimmune disease, transplantation, cancer therapy)

Question 19

What are the common clinically used steroids?

Answer 19

glucocorticoid: cortisone, cortisol, prednisolone, dexamethasone; mineralocorticoid: fludrocortisone

Question 20

Excess aldosterone causes

Answer 20

hypertension (salt and water retention), weakness (hypokalaemia)

Question 21

Aldosterone deficiency causes

Answer 21

dehydration, salt depletion, postural hypotension, cardiac arrhythmias (hyperkalaemia)

Question 22

Conn’s syndrome

Answer 22

adrenocortical tumour secreting excess aldosterone