A catecholamine that is the chemical means of transmission across synapses in postganglionic neurons of the sympathetic nervous system and in some parts of the central nervous system, is a vasopressor hormone of the adrenal medulla and it is a precursor of epinephrine and its major byosynthetic path way.
Sympathetic control of the circulation is carried out through the noradrenergic neuroeffettor system. The nerves make and store noradrenaline, which is released from nerve endings by nerve impulses.