A typical vertebra has an anterior body, two pedicles and two laminae which unite to form a ring bone from which a spinous process protrudes posteriorly and two transverse processes protrude laterally. The first and second cervical vertebra, the atlas and axis however, are atypical.

The atlas no body, but instead has a short and thick anterior arch and a longer posterior arch (grooved superiorly by the vertebral artery). The superior articular facets on its lateral masses are concave and articulate with the occipital condyles of the skull via the atlanto-occipital joints allowing flexion and extension during nodding. The inferior facets are flat and circular, permitting rotation between the atlas and the axis at the atlanto-axial joints.

The axis has an odontoid peg (dens) extending upwards from its body. This peg forms a joint with the internal face of the anterior arch of the atlas and is held in place by the transverse ligament of the atlas (attached to tubercles on the medial aspect of the lateral masses). The transverse ligaments with its longitudinal elements, constitute the cruciform ligament. The apical and alar ligaments further attach the apex of the peg to the skull. These ligaments support the atlanto-axial joints by connecting the atlas, axis, and the occipital bone of the skull.