The automatic (autonomic) nervous system consists of which two divisions?

• A. Cerebral and spinal
• B. Somatic and central
• C. Sympathetic and Parasympathetic
• D. Endocrine and peripheral

Answer: (C)

The key idea is recognizing how the autonomic nervous system organizes its control of involuntary functions. It has two divisions that work in balance to regulate things like heart rate, digestion, and gland activity. The two divisions are the sympathetic system, which prepares the body for action by raising heart rate, dilating airways and pupils, and slowing digestion; and the parasympathetic system, which promotes rest and energy conservation by slowing the heart, stimulating digestion, and promoting relaxation. They often oppose each other to maintain homeostasis and adjust bodily functions as needed. Other options describe parts of the central nervous system or other systems (voluntary control, endocrine, or general peripheral nerves), not the two divisions of the autonomic nervous system.