ABSTRACT
The adrenergic neuroeffector junction consists of the sympathetic neuron, which synthesizes, stores, and releases norepinephrine, and the effector cell. Sympa thetic effector cells in different organs generally have a preponderance of one type of receptor. Alpha (a) refers to the receptors associated with most of the excitatory functions of the sympathetic nervous system, and beta (P) refers to receptors associated with most of the inhibitory functions (1). The myocardium is an important exception to this rule.
