dorsal nerve cord

The dorsal nerve cord is a key structure in chordates, including vertebrates, that develops into the central nervous system. It runs along the back of the organism, above the notochord, which is a flexible rod that provides structural support during early embryonic development and becomes part of the vertebral column in vertebrates. The spinal cord, a major component of the central nervous system, extends from the brain down the vertebral canal and is responsible for reflex actions and transmitting signals between the brain and the rest of the body. It is protected by meninges and cerebrospinal fluid. The spinal cord contains gray matter, which includes cell bodies and interneurons, and white matter, composed of myelinated nerve fibers that form ascending and descending tracts.12345