Adrenal Flashcards
Where are the adrenal glands located?
On top of each kidney
What are the two components of the adrenal gland?
Adrenal medulla
Adrenal cortex
The adrenal cortex secretes 50+ hormones. They are categorized into what 3 groups? (Remember: The 3 S’s)
Glucocorticoids (Sugar)
Mineralocorticoids (Salt)
Androgens (Sex)
What is the most abundant glucocorticoid? (It is necessary for life to continue!)
Cortisol
What does cortisol do?
Stimulates lypolysis in fat tissue
Decreases inflammation
Responds to stress
Maintains fluid volume
What feedback system regulates cortisol?
Negative feedback system (Diurnally)
When are cortisol levels highest?
In the morning
What stimulates cortisol release?
Corticotropin-releasing hormone (CRH) from hypothalamus -> adrenocorticotropic hormone (ACTH) from anterior pituitary -> cortisol from adrenal cortex
What is the primary & most potent mineralocorticoid for maintaining the ECF?
Aldosterone
What does aldosterone do?
Tells kidneys to reabsorb sodium & secrete K+ & H+ ions
What causes aldosterone secretion?
Angiotensin II stimulation (↓ fluid volume/ ↓ BP)
Hyperkalemia
Hyponatremia
What inhibits aldosterone?
Hypokalemia
Atrial natriuretic peptide
What is a disorder of hyperfunction of the adrenal cortex?
Cushing Syndrome
What does hyperfunction of the adrenal cortex mean?
Too much corticosteroids (Cortisol particularly)
What is a disorder of hypofunction of the adrenal cortex?
Addison’s Disease
What does hypofunction of the adrenal cortex mean?
Not enough of all 3 types of corticosteroids
What is the most common cause of Cushing’s?
Iatrogenic (pt took too much corticosteroids – ie Prednisone)
What is the main endogenous cause of Cushings?
Adrenocorticotropic hormone (ACTH) secreting pituitary tumor
What are the main s/s of Cushing’s? (Remember: S/S r/t TOO MUCH STEROID!)
Weight gain (esp. trunk, cervical spine [buffalo hump], moon face)
Hypertension
Hyperglycemia; unexplained Hypokalemia
Osteoporosis (RISK of pathological fx)
Thin skin; easy bruised; depressed purple red striae
Delayed wound healing
What imbalances are expected with Cushing’s?
Hypokalemia
Hyperglycemia
Hypernatremia
When Cushing’s syndrome is suspected, what test is done?
24-hour urine collection for free cortisol (level higher than 120 mcg in 24 hours = Cushing’s)
If results are borderline, what test is done?
Low-dexamethasone suppression test
What is the most important thing to remember about all adrenal gland tests?
Give the test medications at the correct time!
What is the treatment for Cushing’s caused by a tumor?
Adrenalectomy