Which component makes up the Central Nervous System?

• A. The brain and spinal cord
• B. The nerves outside the CNS
• C. The autonomic ganglia
• D. The endocrine glands

Answer: (A)

The central nervous system consists of the brain and spinal cord, serving as the body's main processing and control center. The brain interprets sensory information, coordinates thoughts and actions, and generates responses, while the spinal cord acts as both a conduit for signals between the brain and the body and a site for some reflexes. The other options belong to the peripheral nervous system or to other systems: nerves outside the CNS connect the brain and spinal cord to the rest of the body; autonomic ganglia are clusters of neurons in the peripheral autonomic system; and endocrine glands belong to the hormonal, not nervous, system. So, the brain and spinal cord are the components that make up the central nervous system.