Which of the following is a function of the sympathetic nervous system?

• A. Decreases heart rate and stimulates digestion during rest-and-digest
• B. Initiates voluntary skeletal muscle contraction via motor neurons
• C. Carries sensory information from skin mechanoreceptors to the central nervous system
• D. Increases heart rate and promotes the fight-or-flight response

Answer: (D)

Verified step by step guidance

1. Understand that the autonomic nervous system (ANS) has two main divisions: the sympathetic and parasympathetic nervous systems, each with distinct functions.
2. Recall that the sympathetic nervous system is responsible for the 'fight-or-flight' response, which prepares the body for stressful or emergency situations.
3. Identify that during sympathetic activation, physiological changes include increasing heart rate, dilating airways, and inhibiting digestion to prioritize energy for immediate action.
4. Contrast this with the parasympathetic nervous system, which promotes 'rest-and-digest' activities such as decreasing heart rate and stimulating digestion during relaxed states.
5. Recognize that voluntary skeletal muscle contraction is controlled by the somatic nervous system, and sensory information from skin mechanoreceptors is carried by sensory neurons, not directly by the sympathetic nervous system.