Page 341 - Clinical Anatomy

ECA5 7/18/06 6:51 PM Page 326

326 The head and neck

Fig. 229◊A‘typical’ cervical vertebra.

Fig. 230◊The atlas in superior view.

Fig. 231◊The axis in oblique lateral view.

Just posteriorly to this facet, the upper aspect of the posterior arch of the
atlas is grooved by the vertebral artery as it passes medially and upwards to
enter the foramen magnum.
The axis (C2) (Fig. 231) bears the dens (odontoid process) on the superior
aspect of its body, representing the detached centrum of C1.
Nodding and lateral flexion movements occur at the atlanto-occipital
joint, whereas rotation of the skull occurs at the atlanto-axial joint around
the dens, which acts as a pivot.