The Central Nervous System consists of which structures?

• A. The brain and spinal cord; main function is to process information and activate appropriate reactions.
• B. The peripheral nerves outside the CNS.
• C. A network of glands regulating hormones.
• D. The autonomic and somatic systems only.

Answer: (A)

The central nervous system is made up of the brain and spinal cord. Its main role is to receive information from the body, interpret it, and coordinate appropriate responses. The brain handles processing, decision-making, and planning, while the spinal cord serves as the main highway for messages between the brain and the rest of the body and can also manage quick reflexes on its own. The other options describe parts outside the CNS—the peripheral nerves that make up the peripheral nervous system, the endocrine system of glands, or the autonomic and somatic divisions of the peripheral system—so they don’t define the CNS.