Which describes the peripheral nervous system?

• A. The brain alone
• B. The spinal cord alone
• C. The peripheral nervous system
• D. The autonomic nervous system

Answer: (C)

Understanding how the nervous system is organized helps here. The central nervous system consists of the brain and spinal cord. Everything outside the brain and spinal cord—the nerves and their ganglia that reach into muscles, organs, and sense organs—forms the peripheral nervous system. The PNS connects the CNS to the rest of the body, carrying sensory information to the CNS and motor commands from the CNS. It includes the autonomic division, which handles involuntary functions, and the somatic division for voluntary movement. So describing the peripheral nervous system means referring to the network outside the brain and spinal cord that links the CNS to the body. The brain alone or spinal cord alone are components of the CNS, and the autonomic system is a part of the PNS, not the entire PNS.