Which of the following best describes the primary function of the parasympathetic nervous system?

• A. Fight or flight
• B. Regulation of hormone secretion by the pituitary gland
• C. Control of voluntary muscle movement
• D. Rest and digest

Answer: (D)

Verified step by step guidance

1. Understand that the autonomic nervous system (ANS) has two main branches: the sympathetic and parasympathetic nervous systems.
2. Recall that the sympathetic nervous system is primarily responsible for the 'fight or flight' response, which prepares the body for action in stressful situations.
3. Recognize that the parasympathetic nervous system generally has the opposite effect, promoting 'rest and digest' functions that conserve energy and support maintenance activities.
4. Eliminate options that do not align with the parasympathetic system's role, such as 'fight or flight' (sympathetic function), 'regulation of hormone secretion by the pituitary gland' (endocrine system function), and 'control of voluntary muscle movement' (somatic nervous system function).
5. Conclude that the primary function of the parasympathetic nervous system is best described as 'rest and digest,' which involves slowing the heart rate, increasing digestive activities, and promoting relaxation.