Adrenal Cortex and Medulla Flashcards
Hyperaldosteronism etiologies
primary: from adenoma
secondary: from activation of RAAS
1˚ hyperaldosteronism
etiology
labs: aldosterone and renin
adrenal adenoma
high aldosterone, low renin
2˚ hyperaldosteronism
etiology
labs: aldosterone and renin
fibromuscular dysplasia in young woman, artherosclerosis in older adults
high renin, high aldosterone
Manifestation of hyperaldosteronism
hypertension (increased Na and water reabsorption)
hypokalemia (increased K excretion)
metabolic alkalosis (increased H excretion in alpha intercalated cells)
Aldosterone effects on kidney
in DCT and collecting duct
principle cells: increase Na reabsorption and K excretion
alpha-intercalated cells: excretion of H
Cushing syndrome definition
high cortisol in blood
Presentation of Cushing syndrome
muscle weakness: cortisol breaks down protein
moon facies, buffalo hump, truncal obesity: due to high insulin, fat storage centrally
abdominal striae: due to impaired collagen synthesis and thinning of skin
osteoporosis
How does cortisol cause immunosuppression
inhibit phospholipase A2: no AA metabolites
inhibits IL-2 secretion
inhibits His release from mast cells
Which Cushing syndrome responds to the dexamethasone suppression test
Cushing disease
*primary anterior pituitary ACTH-secreting tumor
Most common cause of Cushings
exogenous glucocorticoids
Adrenal hyperplasia/atrophy in Cushings syndromes:
- exogenous steroids
- ACTH-secreting pituitary adenoma
- ACTH paraneoplastic syndrome
- primary adrenal adenoma, hyperplasia, carcinoma
- exogenous: bilateral atrophy
- ACTH-secreting pituitary adenoma: bilateral hyperplasia
- ACTH paraneoplastic syndrome: bilateral hyperplasia
- primary adrenal pathology: one hyperplasia, one atrophy
- based on fact that ACTH exposure makes them large and lack of ACTH makes them atrophy
Congenital adrenal hyperplasia
etiology
enzymatic defects in cortisol production
Congenital adrenal hyperplasia
why is it hyperplastic?
high ACTH due to negative feedback
leads to hyperplasia of adrenals
Presentation of adrenal hyperplasia
clitoral enlargement in females
precarious puberty in males
Most common subtype of congenital adrenal hyperplasia
21-hydroxylase deficiency
Acute adrenal insufficiency classically caused by
Waterhouse-Fridrichsen syndrome
hemorrhagic necrosis of adrenal glands
2˚ to DIC in young children w/ Neisseria menengitidis infection
lack or cortisol exacerbates hypotension, leading to death
Chronic renal insufficiency
common etiologies
- autoimmune
- tuberculosis infection
- lung mets to adrenals**
Gross appearance Waterhouse-Friderichsen syndrome
“sack of blood” adrenals
Clinical features of Addisons
hypotension, hyponatremia, hypovolemia, hyperkalemia, metabolic acidosis, weakness, hyperpigmentation, vomiting, diarrhea
Adrenal medulla tumor
pheochromocytoma
secretes epi and NE episodically
Pheochromocytoma is tumor of
chromaffin cells in adrenal medulla (neural crest derivation)
Sx of pheochromocytoma
hypertension, headache, palpitations, tachycardia, sweating
Dx of pheochromocytoma
increased serum metanephrines and increased 24-hour urine metanephrines and vanillylmandelic acid
Tx of pheochromocytoma
special consideration before surgery
phenoxybenzamine
irreversible alpha antagonist
prevents hypertensive crisis when surgeon squeezes on tumor
