Cervical Spine

The cervical spine is the first segment of the vertebral column has is composed of 7 cervical vertebrae. The first cervical vertebrae (C1) is named atlas while the second cervical vertebrae (C2) is named axis. The vertebrae are separated from each other by intervertebral discs. The intervertebral discs absorb shock between the individual vertebrae of the spinal column and provide additional protection to the nerves running down spinal column as well.

The parts of the thoracic spine can be categorized as:

Atlas and Axis

Atlas is the first cervical vertebrae (C1). Unlike the other cervical vertebrae, it has no vertebral body or spinous process. Instead, the atlas has a superior articular facet (for articulation with occipital condyles), and an inferior articular facet (for articulation with C2).

Axis is the second cervical vertebrae (C2). It is easily identifiable due to its dens (odontoid process) which extends superiorly from the anterior portion of the vertebra. The dens articulates with the anterior arch of the atlas, creating the medial atlanto-axial joint which allows for rotation of the head independently of the torso. The axis also contains superior articular facets, which articulate with the inferior articular facets of the atlas to form the two lateral atlanto-axial joints.