Kaplan Nursing Entrance Exam Practice 2025 – Comprehensive Prep

The primary role of the sympathetic nervous system is to activate the fight or flight response, which prepares the body to respond to perceived threats or stressors. When the sympathetic nervous system is activated, it results in a series of physiological changes that enable an individual to either confront or escape from danger. These changes include an increase in heart rate, dilation of the bronchial passages, redistribution of blood flow to the muscles, and an increase in blood sugar levels for quick energy.

This response is essential for survival, as it allows a rapid reaction to stressors by enhancing physical capabilities, increasing alertness, and focusing the body's resources where they are most needed in a crisis. The fight or flight response is crucial for handling emergencies but can also relate to chronic stress when it is activated inappropriately over extended periods.

In contrast, the other options related to promoting relaxation, decreasing heart rate during sleep, and increasing appetite during stress are functions associated with the parasympathetic nervous system, which counterbalances the effects of the sympathetic nervous system by promoting rest, digestion, and relaxation.