The peripheral nervous system consists of nerves outside the brain and spinal cord. This statement describes which concept?

• A. It consists only of the brain and spinal cord
• B. It includes only brain tissue
• C. The peripheral nervous system consists of nerves outside the brain and spinal cord
• D. It is not connected to the rest of the body

Answer: (C)

Location-based division of the nervous system helps explain this statement. The peripheral nervous system includes all nerves outside the brain and spinal cord, such as cranial and spinal nerves and autonomic nerves that connect the CNS to muscles, glands, and sensory receptors. Describing the PNS this way is accurate because it defines the PNS by its position relative to the central nervous system—the CNS being the brain and spinal cord, while the PNS forms the communication network to the rest of the body. Saying the system consists only of the brain and spinal cord would describe the central nervous system, and claiming it includes only brain tissue would be incorrect because brain tissue is part of the CNS. The idea that it is not connected to the rest of the body contradicts its role as the network linking the CNS to all body parts.