The autonomic nervous system comprises which two parts?

• A. Sympathetic, parasympathetic
• B. Somatic, autonomic
• C. Central, peripheral
• D. Cranial, spinal

Answer: (A)

The autonomic nervous system is the part of the nervous system that controls involuntary functions like heart rate, digestion, and pupil size. It has two main divisions: the sympathetic and the parasympathetic. The sympathetic branch prepares the body for action (fight-or-flight), speeding up the heart and freeing energy, while the parasympathetic branch promotes rest and digestion, slowing the heart and aiding nutrient processing. These two divisions often balance each other to maintain stability in the body's internal environment.

Other groupings don’t describe the autonomic system’s two functional parts: the somatic system handles voluntary movement and conscious sensation; central vs peripheral refers to where nerves are located in the nervous system as a whole; and cranial vs spinal describes where nerves emerge from the CNS, not the two divisions that specifically govern involuntary control.