Diseases of the adrenal glands include adrenal insufficiency (due to an infection, hemorrhage, or autoimmune destruction), hyperaldosteronism (due to hyperplasia or adenoma), and hypercortisolism (due to hyperplasia, adenoma, or exogenous administration). Mineralocorticoids regulate renal sodium and water reabsorption and potassium excretion, while glucocorticoids play an important role in glucose metabolism. The adrenal cortex consists of three layers: the zona glomerulosa, the zona fasciculata, and the zona reticularis, which are responsible for the synthesis of mineralocorticoids, glucocorticoids, and androgens (precursors for estrogen and testosterone), respectively. The adrenal medulla is composed of chromaffin cells, which secrete catecholamines ( norepinephrine, epinephrine, dopamine). The adrenal gland has two layers: the adrenal cortex (outer layer), which is derived from the mesoderm, and the adrenal medulla (inner layer), which is derived from neural crest cells. The lymphatics drain into the left aortic and the right caval lymph nodes. It receives its arterial supply from the superior, middle, and inferior suprarenal arteries and drains into the right and left suprarenal veins.
The adrenal gland is a paired retroperitoneal organ located on the upper pole of each kidney.
