Adrenal Flashcards
what does the zona glomerulosa produce?
mineralocorticoids and aldosterone
what does the zona fasciculata produce?
glucocorticoids and cortisol
what does the zona reticularis produce?
sex steroids and glucocorticoids
what do the neuroendocrine (chromaffin) cells of the medulla secrete
catecholamines
what are the causes of hyper function?
hyperplasia, adenoma, carcinoma
what are the causes of hypo function?
acute: waterhouse-Friderichsen
Chronic: Addisons
what is congenital adrenocortical hyperplasia?
group of autosomal recessive disorders, lack of enzyme required for steroid biosynthesis
what is acquired adrenocortical hyperplasia?
endogenous ACTH production
what is Conns syndrome?
primary hyperaldosteronism
what happens in secondary hyperaldosteronism?
increase in renin
where can you see pigmentation in Addisons disease?
buccal mucosa and palmar surfaces
what are the two adrenal medullary tumours?
phaeochromocytoma and neuroblastoma
what is Phaeochromocytoma?
neoplasm derived from chromaffin cells of the adrenal medulla, secretes catecholamines
what are the nests of tumour cells called in phaeochromocytoma?
zellballen
Phaeochromocytoma is a feature of?
MEN = multiple endocrine neoplasia
what syndrome is otherwise known as MEN(2A)
sipple syndrome
what makes up Sipple syndrome?
Phaeochromocytoma, medullary thyroid carcinoma, parathyroid hyperplasia
what genetic abnormality is Sipple syndrome linked to?
RET oncogene
what makes up MEN(2B)
phaeochromocytoma, medullary thyroid carcinoma, neuromas/ganglioneuromas and marfanoid habitus
what is a synacthen test?
synthetic ACTH
what is the result of a normal synacthen test?
over 550
what are the layers of the adrenal gland from lateral to medial
ZG, ZF, ZR and medulla
what compound is the starting point in the biosynthesis of corticosteriods?
cholesterol
what is the rate limiting step in the biosynthesis of corticosteroids?
conversion of cholesterol to pregnenlone
what is aldosterone regulated by?
renin-angiotensin system and plasma potassium
when is cortisol at its peak?
8/9am
effect of cortisol on the circulatory/renal system?
increase cardiac output, increase BP and increase blood flow
effect of cortisol on the CNS
mood, decrease libido
effect of cortisol on the bone
accelerate osteoporosis, decrease calcium/collagen formation/wound healing
effect of cortisol on the metabolic system?
increase in food stuff breakdown
what receptor does aldosterone work on?
mineralocorticoid receptor
what are the effect on NA and K in addisons?
decreased NA, increase K
what do we give as cortisol replacement?
Hydrocortisone
what do we give as aldosterone replacement?
Fludrocortisone
what kind of structures are the adrenal glands?
retroperitoneal
what hormones are secreted from the medulla?
adrenaline and nor-adrenaline
if the Aldosterone to Renin ratio is over 750 what do we do?
saline suppression test
what is a plethoric complexion or ‘moon face’?
redistribution of fat around the body in cushings
what are paraganglia cells?
collections of adrenaline secreting chromaffin cells
what is Phaeochromocytoma caused by?
catecholamine secreting tumours which arise from sympathetic paraganglia cells
