Norepinephrine - definition from Biology-Online.org
[noradrenaline (Science: drug, hormone) catecholamine neurohormone, the neurotransmitter of most of the sympathetic nervous system (of so called adrenergic neurons): binds more strongly to _ adrenergic receptors. stored and released from chromaffin cells of the adrenal medulla. A catecholamine precursor of epinephrine that is secreted by the adrenal medulla and also released at synapse. Responsible for the flight or fight reaction.