Compound glands located at the top of the kidneys.
They have an outer zone known as cortex and an inner one known as medulla. The
cortex secretes a complex of substances appearing to be closely related
chemically. Their combined action controls sodium, potassium, and chloride
metabolism, which affects water balance, causes the change of glycogen to
glucose, and influences sex. Deficiency results in a syndrome known as Addison's
disease. The patient suffering from it experiences a general decline in muscular
strength and sexual activity, a lowering of blood pressure, disturbance of
digestion, and a bronzing of the skin. The best-known cortical secretion is
cortisone, which has been used in treating arthritis and allergies. The medulla
secretes a hormone called epinephrine (adrenaline), which is produced in
accelerated quantities when one is stimulated by anger or fear. Apparently it is
the only endocrine gland directly responding to nervous stimuli. The influence
of epinephrine on the conversion of glycogen to glucose, stimulation of heart
muscles, enrichment of blood supply to muscles, and acceleration of blood
coagulation are without doubt useful to provide more and quick energy or to stop
bleeding in times of
stress or
injury.
