Section 1: Anatomy of the Spinal Cord

CERVICAL SPINAL CORD 

The cervical spinal cord begins as the medulla oblongata emerges from the foramen magnum, at the level of the atlanto-occipital joint.

It gives off 8 paired spinal nerves. The superiormost seven nerves--called C1-C7--(one on each left and right) exit the vertebral canal through intervertebral foramina above their respective vertebrae. The eighth cervical nerve--called C8--exits the vertebral canal through the intervertebral foramen created by the articulation of the seventh cervical and first thoracic vertebrae.

In cross-section, the cervical cord is the largest of the four divisions of the spinal cord. It is somewhat oblong and has a large, well-defined ventral horn, especially in segments C5 - C8, which contribute to the brachial plexus to control the upper extremities.

Figure 1.1: Cross-section of the cervical spinal cord, with Rexed Laminae shown