What major components make up the central nervous system?

The central nervous system (CNS) is primarily composed of the brain and spinal cord. The brain serves as the control center for processing information and coordinating bodily functions, while the spinal cord acts as a conduit for signals between the brain and the rest of the body. Together, they integrate sensory information, regulate motor functions, and are responsible for higher cognitive functions such as thought and emotion.

In contrast, the heart and lungs are part of the cardiovascular and respiratory systems, respectively; muscles and tendons belong to the musculoskeletal system, providing movement and support; and the eyes and ears are sensory organs that play roles in vision and hearing but are not components of the CNS. Therefore, understanding that the brain and spinal cord comprise the CNS is crucial for grasping its pivotal role in coordinating and regulating bodily functions.