PT14

What are the 3 zones of the adrenal gland?

Zona, glomerulosa, fasciculata, recticularis

What is the overall function of the adrenal gland?

Coordinated response to stress

Define congenital adrenal hyperplasia

Defective steroid synthesis end up with build of precursors which may stimulate the synthesis of other hormones

What is the role of aldosterone?

Increase the reabsorption of Na and increase secretion of K and H

What is mineralocorticoid receptor?

A nuclear receptor, modulated transcription of certain genes, NA/K ATPase pump, restricted to kidney, colon, bladder

What is the secretion of aldosterone stimulated by?

Changes in blood pressure, increase in sympathetic nervous cells, macular densa sensed decrease in sodium chloride delivery in DCT,

What is the function of Angiotensin II?

Constricts blood vessels, triggers adrenal gland to release aldosterone

Describe spironolactone?

Competitive antagonist of spironolactone, has some androgen blocking action

Describe fludrocortisone?

Used as aldosterone replacement in addison’s disease

Describe primary hyperaldosteronism?

Conn’s syndrome, too much aldosterone, can be caused by adrenal hyperplasia, or a secreting adenoma

Describe the risks associated with primary hyperaldosteronism

Risk of stroke, heart disease, kidney failure

How to test for primary hyperaldosteronism

Increase aldosterone: renin ratio, high levels of aldosterone not suppress by saline solution, increase urinary K

What are cortisol’s main influences?

Cardiovascular, metabolic, immunogenic, homeostatic functions

What are the synthesis and secretion of cortisol reliant on?

ACTH from pituitary

What is cortisol’s main function?

Glucose metabolism, in response to stress, mobilise it into the blood stream

Define addison’s disease?

Primary adrenal insufficiency, most often autoimmune against the gland, characterised by increased ACTH production, which stimulates hyperpigmentation

Define secondary adrenal insufficiency?

Hypofunction due to impaired ACTH, often due to medication for a non endocrine disorder, inflammatory usually

What are the risk factors of adrenal insufficiency?

Hypotension, hyperkalaemia, hypoglycaemia, dehydration

Long term management of hypoadrenalism?

Replacement therapy with glucocorticoid and mineralocorticoid

What is the common cause of adrenal insufficiency in childhood?

Congenital Adrenal Hyperplasia; CAH

Describe Cushing’s syndrome

Hypercortisolism, primary due to overactive adrenal gland, secondary due to increased secretion of ACTH via tumour, iatrogenic

What ae the risk factors of cushing syndrome>

Affects metabolism, redistribution of fats, hypertension, poor wound healing, thin skin, stretch marks, MI, infections, heart failure

What is the test for cushing’s syndrome?

Give glucocorticoid should get negative feedback reducing ACTH, levels stay the same of high indicative of Cushing’s syndrome

Management of Cushing’s syndrome?

Surgery or radiotherapy, hypersecretion must be controlled prior to this, metyrapone, ketoconazole