What structures comprise the central nervous system?

• A. Brain and spinal cord
• B. Peripheral nerves
• C. Muscles and bones
• D. Autonomic ganglia

Answer: (A)

The central nervous system consists of the brain and spinal cord. These two structures serve as the main processing and command center, interpreting sensory information and issuing motor instructions. They’re protected by the skull and vertebral column, plus protective membranes and cerebrospinal fluid. The peripheral nervous system, including the nerves that extend to limbs and organs and the autonomic ganglia, connects the CNS to the rest of the body. Muscles and bones are not nervous tissue; they are the tissues that respond to neural signals. So, the brain and spinal cord are the components that make up the central nervous system.