The adrenal gland is divided into the adrenal medulla, which
produces catecholamines such as epinephrine and norepinephrine,
and the adrenal cortex, which produces cortical steroids such as
cortisol, aldosterone, and androgens, all of which are needed to
maintain homeostasis in the body. The adrenal cortex is further
subdivided into 3 regions: the zona glomerulosa, which is
responsible for producing mineralocorticoids (eg, aldosterone);
the zona fasciculata, which secretes glucocorticoids (eg,
cortisol); and the zona reticularis, which releases androgens
(eg, testosterone).1,2 The levels of these cortical steroids are
regulated through the hypothalamuspituitary-adrenal (HPA) axis
(Figure). In response to inadequate levels of cortical steroids
in the body, the hypothalamus will secrete corticotropin-
releasing hormone (CRH), which exerts a positive feedback on the
anterior pituitary gland to release adrenocorticotropic hormone
(ACTH). ACTH then stimulates the release of cortical steroids
from the adrenal gland.