Adrenergic Receptors

Epinephrine (adrenaline, A) and norepinephrine (noradrenaline, NA) are naturally occurring catecholamines that are rmportant in many physiological processes. Adrenaline is found in high concentrations in the adrenal medulla, where it is released into the blood to function as a hormone. Noradrenaline is the major neurotransmitter of postganglionic sympathetic nerves and is particularly important in control of cardiovascular function. Both catecholamines also control metabolic processes in many glands and muscles. In addition, both A and NA are found in specific neurons of the central nervous system, where they function as neurotransmitters and play important roles in a variety of in-tegrative functions, such as control of autonomic outflow, mood, and appetite.