The adrenal hormones are crucial for the body's electrolyte balance and stress response. The adrenal cortex produces over two dozen types of corticosteroid hormones. The zona glomerulosa produces mineralocorticoids, such as aldosterone, that affect the electrolyte composition of body fluids. The zona fasciculata produces steroid hormones such as cortisol and corticosterone. They are collectively known as glucocorticoids because they affect glucose metabolism. In the liver, glucocorticoids speed up glucose synthesis, and in muscle and adipose tissue, they promote glycogen formation. The zona fasciculata also produces smaller amounts of androgens. Adrenal androgens stimulate the development of pubic hair in adolescents. In adult women, they promote muscle mass and blood cell formation and support the sex drive. The adrenal medulla contains two types of chromaffin cells that secrete catecholamines in response to stress. One type produces epinephrine and the other norepinephrine. These are continuously packaged in vesicles and released at low levels by exocytosis. These hormones promote strength and endurance in skeletal muscles and break down stored fat and glycogen in the adipose tissue and liver.