The parasympathetic nervous system is best described as

• A. The fight or flight system.
• B. The rest and digest system that governs routine conditions.
• C. The system that controls reflexes.
• D. The system that modulates arousal.

Answer: (B)

The parasympathetic nervous system is responsible for rest and maintenance functions that occur during quiet, routine conditions. It slows the heart rate, promotes digestion and nutrient absorption, stimulates saliva and other secretions, constricts the pupils, and supports energy storage and recovery processes. In short, it fosters calm, restorative activities and helps conserve energy after stress. This is the opposite of the sympathetic system, which prepares the body for action through heightened arousal and mobilization of energy. So describing the parasympathetic as the rest and digest system that governs routine conditions best captures its role.