Which of the following statements is correct concerning the parasympathetic division of the autonomic nervous system (ANS)?

• A. It is responsible for the 'rest and digest' response.
• B. It primarily uses norepinephrine as its main neurotransmitter at the effector organ.
• C. Its preganglionic fibers are shorter than its postganglionic fibers.
• D. It increases heart rate and dilates pupils.

Answer: (A)

Verified step by step guidance

1. Understand the role of the parasympathetic division of the autonomic nervous system (ANS). It is responsible for the 'rest and digest' response, which promotes relaxation, digestion, and energy conservation.
2. Recall the neurotransmitter used by the parasympathetic division. The parasympathetic division primarily uses acetylcholine (ACh) as its neurotransmitter at both the preganglionic and postganglionic synapses, not norepinephrine.
3. Analyze the structure of parasympathetic fibers. The parasympathetic division has long preganglionic fibers and short postganglionic fibers, which is opposite to the sympathetic division.
4. Evaluate the physiological effects of the parasympathetic division. It decreases heart rate, constricts pupils, and promotes digestion, contrasting with the sympathetic division's 'fight or flight' response.
5. Compare the given statements to the characteristics of the parasympathetic division. Identify the correct statement as the one that aligns with its 'rest and digest' function.