Chapter 4 - Adrenal Glands

Abstract

This chapter summarizes the development and morphology of adrenal glands and the biosynthesis, functions, and regulation of its hormones. Adrenal glands are complex polyfunctional organs that secrete hormones that are required for maintenance of life. Without adrenal hormones, deranged electrolyte or carbohydrate metabolism leads to circulatory collapse or hypoglycemic coma and death. There are three major categories of adrenal steroid hormones: mineralocorticoids, which act to defend the body content of sodium and potassium; glucocorticoids, which affect body fuel metabolism, responses to injury, and general cell function; and androgens, which function in a manner similar to that of the hormone of the male gonads. The adrenal cortex is essential for maintenance of life. Insufficiency of adrenal cortical hormones (Addison's disease) produced by pathological destruction or surgical removal of the adrenal cortices results in death within 1 to 2 weeks unless replacement therapy is instituted. All of the adrenal steroids are derivatives of the polycyclic phenanthrene nucleus, which is also present in cholesterol, ovarian and testicular steroids, bile acids, and precursors of vitamin D. Adrenal cortical hormones are transported in blood bound to the specific plasma protein transcortin, or corticosteroid-binding globulin (CBG), and to a lesser extent to albumin. Glucocorticoids dramatically reduced the severity of disease in patients suffering from rheumatoid arthritis.