Spinal cord

The spinal cord is part of the CNS, and relays information from and to the brain, as well as mediating movements by itself.

Law of Bell and Magendie
The dorsal root always carries sensory information, and the ventral root aways motor information.

Segmentation
It lies within a spinal column, made up of bones called vertebrae. These are categorized into five regions, to which the nerves from the SNS connect. These are called spinal nerves.