Figure 1.

A diagrammatic illustration of the role of the two arms of the autonomic nervous system. Note that in general the actions of the sympathetic nervous system are illustrated as being in the opposite direction to that of the parasympathetic nervous system. Not shown here but discussed below is the CNS regulation of the immune system via the vagal cholinergic anti-inflammatory pathway adding yet another dimension to the role of the autonomic nervous system in survival of the organism. Note that Kurt Vonnegut recognized the importance of the CNS in stress but failed to recognize its role as the conductor of the endocrine and autonomic orchestra. But then he was not a biologist!