Advanced Dental Admission Test (ADAT)

Which part of the autonomic nervous system is represented by the vagus nerve?

1. Sympathetic

2. Somatic

3. Parasympathetic

4. Central

The correct answer is: Parasympathetic

The vagus nerve plays a crucial role in the parasympathetic branch of the autonomic nervous system. It is the longest cranial nerve and innervates multiple organs, including the heart, lungs, and digestive tract, thereby influencing a variety of involuntary physiological functions. The parasympathetic nervous system is responsible for promoting the "rest and digest" state, which helps the body conserve energy and maintain homeostasis. In contrast, the sympathetic nervous system is responsible for the body's "fight or flight" responses, while the somatic nervous system is associated with voluntary control of skeletal muscles. The central nervous system encompasses the brain and spinal cord, but it is distinct from the peripheral nervous system, where the vagus nerve is located. Thus, the unique functions and pathways of the vagus nerve clearly align it with the parasympathetic division.