The spinal cord lies in the vertebral canal and in adults, begins at the top of the first cervical vertebra and stops at the bottom of the first lumbar vertebra (a distance of between 42 and 45 cm).
The spinal cord is divided into cervical, thoracic, lumbar, sacral and coccygeal regions.
The peripheral nerves that innervate the body arise from the spinal cord as 31 pairs of segmental spinal nerves.
Sensory information is carried to the spinal cord from the peripheral nerves and enters the spinal cord via the dorsal roots.
Motor commands leave the spinal cord via the ventral roots where they travel along nerve axons to the periphery.
Like the forebrain, the spinal cord is made up of grey matter and white matter.
The interior of the cord contains the grey matter and is surrounded by a cylindrical mass of white matter, organised into discrete areas relating to the specific body functions they control.