OSMT Ontario Practice Exam Prep - Practice Test and Study Guide

The central nervous system (CNS) is comprised of the brain and spinal cord. This is crucial as the CNS serves as the main control center for the body, responsible for processing sensory information, coordinating responses, and facilitating communication between different parts of the body.

The brain functions as the major processing unit, while the spinal cord acts as a conduit for signals between the brain and the rest of the body. In contrast, the other choices refer to components of the peripheral nervous system (PNS) and do not form part of the CNS. Peripheral nerves and somatic nerves are involved in transmitting signals to and from the limbs and organs, whereas spinal nerves branch out from the spinal cord into the periphery. Thus, the correct identification of the CNS as solely including the brain and spinal cord highlights its primary role in the body's neurological framework.