Adrenal 1 Flashcards
What are the different parts of the adrenal gland and what does each section secrete?
- Cortex (Can think “GFR–> ACE”)
- outer: Zona Glomerulosa–> Aldosterone
- middle: Zona Fasciculata –> Cortisol
- Inner: Zona Reticularis –> Androgens/DHEA (think Estrogens for mnemonic)
- Medulla–> Catecholamines (NE and Epi)
Aldosterone vs. cortisol: which is the mineralcorticoid? Which is the glucocorticoid?
Aldosterone= mineralcorticoid (“Al mines”)
Cortisol= Glucocorticoid
Which hormone is pulsatile and diurnal (AM>PM)?
Cortisol
What is cortisol under control of
ACTH
Which hormone?
- Stress, trauma, etc cause release
- Protects against hypoglycemia
- Inhibits production of inflam. mediators
- Suppression of immune response
- Enhance vascular responsiveness to catecholamines
Cortisol
Which hormone?
- Increases force/rate of contraction of heart
- Vasoconstriction
- Bronchodilation
- Stimulation of lipolysis
- Increase metabolic rate
- pupil dilation
- Inhibition of non-essential processes
Catecholamines (Epi/NE)
What is the long term response to stress? (
- Mineralcorticoids (Aldosterone)
- retention of Na and H20
- Incr. blood volume and BP
- Glucocorticoids (cortisol)
- protein and fats converted to glucose
- hyperglycemia
- suppression of immune system
Is a stimulation test used to evaluate for hypo or hyperfunction? A suppression test?
Stimulation test= hypofunctioning
Suppression test= Hyperfunctioning
What is 24hr urinary free cortisol a test for
hypercortisolism
What does a serum cortisol value <3mg/dL on a serum total cortisol test very likely indicate?
Adrenal insufficiency
What is the main use of obtaining a plasma ACTH?
Adrenal insufficiency:
Differentiate primary (adrenal) vs secondary (pituitary) vs. tertiary (hypothalmic)
What does an ACTH stimulation test (using synthetic ACTH- Cosyntropin) evaluate for?
Differentiate source of adrenal insufficiency (cortisol deficiency)
(if no increase from baseline= adrenal insufficency)
What would an ACTH stimulation test show in adrenal insufficiency?
Subnormal cortisol level response
What does the following indicate on a Dexamethasone suppresion test:
No change in cortisol
= Excess cortisol production
(normal would be cortisol suppressed)
What are the 4 causes of Cushings syndrome? (hypercortisolism)
- ACTH dependent (MC)
- Pituitary adenoma (MC overall)–> cushings DISEASE
- NET producing ACTH- small cell lung cancer, ovarian cancer
- ACTH independent
- Chronic glucocorticoid use (2nd MC)
- Adrenocortical tumor (benign or malignant
What are the 2 MC causes of Cushings syndrome?
- Pituitary adenoma (MC overall, ACTH dependent)–> Cushings Disease
- Chronic glucocorticoid use (ACTH independent)
What is Cushings Sydrome?
Signs and symptoms due to prolonged exposure to excess cortisol
(Cushings Disease is de to Pituitary adenoma)
S/s of what?
- Central obesity
- moon face
- cervical fat pad
- Purple abdominal striae
- Fatigue
- Prox mm. weakness
- HTN
- Insulin resistance
Cushings syndrome