Which effect characterizes the sympathetic division of the autonomic nervous system?

• A. Fight or flight
• B. Rest and digest
• C. Sleep and wake
• D. Digestive inhibition

Answer: (A)

The main idea here is what the sympathetic division does in the autonomic nervous system. Its hallmark is fight or flight—the body’s rapid preparation for immediate action in response to stress. When this system activates, heart rate and breathing often increase, pupils dilate, blood is redirected to the muscles, glucose is released for quick energy, and digestion slows down. This global state is about gearing the body up for quick, energetic responses to a threat.

Rest and digest describes the parasympathetic division, which promotes relaxation, conservation of energy, and digestion, opposite to the sympathetic state. Sleep and wake isn’t a specific autonomic-twin descriptor, and digestive inhibition is just one consequence of sympathetic activation, not the overall role. The fight or flight description best captures the sympathetic system’s primary effect.