The cervical spine consists of seven vertebrae and is located at the base of the skull. Its function is to support the skull, enabling head movements back and forth, and from side to side, as well as protecting the spinal cord.  The upper section of the cervical spine consists of the first cervical vertebrae (C1) and the second cervical vertebrae (C2). The lower section consists of the third cervical vertebrae (C3) through seventh cervical vertebrae (C7). These spinal bones attach to the thoracic spine and work together to support the head.

Spinal bone three is directly in line with the lower section of the human jaw and the hyoid bone, which is a horseshoe-shaped bone located inside the neck that holds the tongue in place. Just like the other six spinal bones, spinal bone three is quite flexible, giving it the ability to aid in the bending and rotation of the neck. The fourth cervical vertebrae (C4) nerve root extends from the third cervical vertebrae (C3).

Injury to spinal bone three often causes pain, tingling, and sometimes numbness in the arms, neck, and head. If the fourth cervical vertebrae (C4) nerve root is also involved, pain is usually felt in the upper arms and shoulders, as well as the lower neck.