Which are the divisions of the autonomic nervous system?

• A. Autonomic Nervous System
• B. Sympathetic and Parasympathetic
• C. Central and Peripheral
• D. Somatic and Autonomic

Answer: (B)

The autonomic nervous system has two divisions that regulate involuntary functions: the sympathetic and the parasympathetic. The sympathetic division prepares the body for stress or activity—think increased heart rate, widened airways, and pupil dilation—while the parasympathetic division promotes resting and digesting activities, such as slowing the heart rate and stimulating digestion. These two systems usually act in opposition to maintain a stable internal environment.

Other options describe either the whole autonomic system, general nervous system components, or a broad division between voluntary and involuntary control, rather than the specific subdivisions of the autonomic nervous system itself.