Each kidney has an adrenal gland
located above it. The adrenal gland is divided into an inner
medulla and
an outer cortex. The medulla
synthesizes amine hormones, the cortex secretes steroid
hormones. The
adrenal medulla consists of modified
neurons that secrete two hormones: epinephrine and
norepinephrine.
Stimulation of the cortex by the
sympathetic nervous system causes release of hormones into the
blood to
initiate the "fight or flight"
response. The adrenal cortex produces several steroid hormones
in three
classes: mineralocorticoids,
glucocorticoids, and sex hormones. Mineralocorticoids maintain
electrolyte
balance. Glucocorticoids produce a
long-term, slow response to stress by raising blood glucose
levels
through the breakdown of fats and
proteins; they also suppress the immune response and inhibit the
inflammatory response.