ABSTRACT
The autonomic nervous system is the visceral motor system. It adjusts the contraction of smooth muscle and heart muscle and controls glandular secretion so that key physiological variables (e.g., core temperature, cardiac output, blood pressure, blood glucose) are maintained at levels appropriate to the environment or ongoing activities. The term autonomic (self-governing) is apt since the ANS usually operates without conscious 275awareness and has no cognitive component. Although by definition there are no afferents in the ANS its reflex activities are controlled by somatic and visceral afferent input.
