The spinal cord is a long, cylindrical structure that runs down the center of the back, encased within the vertebral column or spine. It is a crucial part of the central nervous system, connecting the brain to the rest of the body. The spinal cord is responsible for transmitting nerve signals that control movement and sensation. Made up of nerve fibers, the spinal cord is divided into segments that correspond to different regions of the body. It also contains reflex pathways that allow for quick responses to stimuli, such as pulling your hand away from a hot surface, without needing to involve the brain directly.