Which term refers to the brain and spinal cord collectively?

• A. Central nervous system
• B. Peripheral nervous system
• C. Cerebral cortex
• D. Autonomic nervous system

Answer: (A)

The central nervous system consists of the brain and spinal cord, serving as the main processing and control center for the nervous system. The brain interprets sensory information, thoughts, and memories, while the spinal cord carries signals to and from the brain and coordinates many reflexes. This is why the term that describes both structures together is the central nervous system.

The peripheral nervous system includes all nerves outside the brain and spinal cord, connecting the CNS to muscles and organs. The cerebral cortex is just the outer layer of brain tissue involved in higher functions, not the entire CNS. The autonomic nervous system is a division of the peripheral nervous system that governs involuntary functions like heart rate and digestion, not the whole CNS.