The cervical spine is the first seven bones of the vertebral column and extends from the base of the skull to the top of the thoracic spine. Each of the first two vertebrae has a unique shape and function.
The skull rests upon the first vertebra, called the atlas, which serves as a pivot. Its design allows for forward and backward motion of the head, such as for making a "yes" motion. The axis sits below the atlas and is designed for rotation. A bony process, called the dens, articulates with the atlas allowing the head to turn from side to side, such as for making a "no" motion.
Each of the five remaining vertebrae has a weight-bearing body. Surrounding these vertebrae are muscles, ligaments, blood vessels, and nerves.
In addition, intervertebral disks between the vertebrae act as shock absorbers for the spine. The design of the cervical vertebrae provides structural support and allows for considerable flexibility of the head and neck.