Which two parts compose the central nervous system?

The central nervous system (CNS) is composed of two main structures: the brain and the spinal cord. The brain serves as the control center for processing information and coordinating bodily functions, while the spinal cord acts as a critical pathway for transmitting signals between the brain and the rest of the body. Together, they facilitate communication, response to stimuli, and the overall functioning of the body.

Other options, while including components of the nervous system, do not accurately represent the central nervous system. The rectum, for example, is part of the digestive system and is not involved in the CNS. The cerebellum, while a significant part of the brain responsible for coordination and balance, does not stand alone as a component separating it from the spinal cord. Lastly, peripheral nerves belong to the peripheral nervous system, which works in conjunction with the CNS but is distinct from it. Understanding the fundamental roles of the brain and spinal cord within the central nervous system is essential for grasping the overall structure and function of the human nervous system.