Which statement correctly describes the overall division of the autonomic nervous system?

• A. Sympathetic handles rest and digest; Parasympathetic handles fight or flight.
• B. Sympathetic handles fight or flight; Parasympathetic handles rest and digest.
• C. Both divisions handle rest and digest equally.
• D. Neither division influences autonomic functions.

Answer: (B)

The autonomic nervous system is organized into two main divisions that typically have opposite actions: one prepares the body for action, the other promotes rest and maintenance. The division responsible for fight-or-flight responses ramps up activity—heart rate and cardiac output increase, airways dilate, energy is mobilized, and digestion is slowed. The other division promotes rest-and-digest activities—slowing the heart, constricting pupils, stimulating digestion, and conserving energy for routine maintenance. Because of these complementary roles, the accurate description is that the fight-or-flight function is handled by the first division, while the rest-and-digest functions are handled by the second division. The other statements conflict with this well-established division of labor, or incorrectly claim equal involvement in these states or no influence at all.