Which components make up the central nervous system?

• A. Brain and spinal cord
• B. Brain and nerves
• C. Spinal cord only
• D. Nerves and ganglia

Answer: (A)

The brain and spinal cord are the components that make up the central nervous system, where most processing, integration, and coordination occur. The brain interprets sensory information and plans actions, while the spinal cord serves as the main highway connecting the brain to the rest of the body and can also control some reflexes independently. Structures like nerves and ganglia belong to the peripheral nervous system, which covers the pathways that connect the CNS to muscles and organs. Because the central nervous system comprises only the brain and spinal cord, that option is the correct one. The other choices either include peripheral elements or omit one of the CNS components.