A hormone produced by the adrenal medulla, similar in chemical and pharmacological properties to epinephrine (also a hormone secreted by the adrenal medulla in response to stimulation of the sympathetic nervous system). Norephinephrine and epinephrine are the two active hormones that cause some of the physiological expressions of fear and anxiety, and have been found to be in excess in some anxiety disorders when a disturbance in their metabolism occurs.
See Adrenal medulla, Catecholamines, Attention deficit hyperactivity disorder (ADHD), Epinephrine (or adrenaline), Hormones, Locus coeruleus (or ceruleus), Mesencephalic reticular activating system, Neurotransmitters, Noradrenergic neurotransmitter system, Sympathetic nervous system (SNS)