Biological Systems MCAT Practice Exam

What are the two main categories of the peripheral nervous system?

1. Central and autonomic

2. Somatic and autonomic

3. Sympathetic and parasympathetic

4. Cranial and spinal

The correct answer is: Somatic and autonomic

The correct classification of the peripheral nervous system into main categories consists of the somatic nervous system and the autonomic nervous system. The somatic nervous system is responsible for voluntary control of skeletal muscles and the relay of sensory information from the body to the central nervous system. This includes actions like walking, speaking, and other conscious movements. The autonomic nervous system, on the other hand, regulates involuntary functions such as heart rate, digestion, and respiratory rate. This system is further divided into the sympathetic, parasympathetic, and enteric nervous systems, which work together to maintain homeostasis and respond to stress. In contrast, the central nervous system is comprised of the brain and spinal cord, which process information but is not classified as part of the peripheral nervous system. Choices referencing only sympathetic or parasympathetic divisions focus on subsets of the autonomic nervous system rather than the broader categories. Lastly, the classification of cranial and spinal refers to types of nerves rather than overarching categories of the peripheral nervous system itself.