Adrenal Glands

About the Adrenal Glands

The adrenal glands are paired triangular organs atop each kidney, weighing approximately 4 to 6 grams each. Each gland has two distinct functional zones. The adrenal cortex 80 percent produces steroid hormones in three layers: zona glomerulosa aldosterone salt and water balance, zona fasciculata cortisol stress, metabolism, anti inflammatory, and zona reticularis DHEA and androgens. Aldosterone is regulated by the RAAS and potassium. Cortisol follows a circadian rhythm peaking at 6 to 8 AM and is regulated by ACTH CRH. The adrenal medulla 20 percent is modified sympathetic ganglion producing epinephrine 80 percent and norepinephrine 20 percent in response to sympathetic stimulation, preparing the body for fight or flight. Addison disease primary adrenal insufficiency causes fatigue, hypotension, hyperpigmentation, hyponatremia, hyperkalemia. Cushing syndrome excess cortisol causes central obesity, moon face, buffalo hump, striae, hypertension, diabetes. Pheochromocytoma from medulla causes episodic hypertension, palpitations, headache, sweating. Congenital adrenal hyperplasia 21 hydroxylase deficiency causes salt wasting and virilization. Pheochromocytoma was classically taught with a rule of 10s, although genetic studies have since shown that a much larger share of these tumors are hereditary than that rule suggests.