The spinal cord begins cranially from the foramen magnum as the continuation of the medulla oblongata, which is the lower part of the brainstem.

It then descends within the vertebral canal of the spine reaching the level of second lumbar vertebra (L2), where it tapers off forming a tip, which is called conus medullaris.

Because it ends at L2, the spinal cord occupies two-thirds of the spinal canal.

Within the canal it is covered by the spinal meninges filled with cerebrospinal fluid.

Two depressions are present on the surface of the spinal cord:

• Anterior median fissure - a deep groove that extends the length of the anterior surface of the spinal cord;
• Posterior median fissure - a slightly shallower groove on its posterior surface.

The spinal cord consists of the cervical, thoracic, lumbar, sacral, and coccygeal parts, each consisting of several segments.

There are 31 segments defined by 31 nerves exiting the spinal cord, which are divided into the following sets of nerves:

• 8 cervical
• 12 thoracic
• 5 lumbar
• 5 sacral
• 1 coccygeal

Spinal nerves arising from the distal part of the spinal cord (L2 - S5) create a bundle called the cauda equina.