Atlas and Axis

The first two cervical vertebrae  are the atlas (C1)  and the axis (C2.)

The atlas is named for the character from Greek Mythology who supported the globe, though in anatomy, the head is the globe.  In fact, the articular facets of the atlas align perfectly with the occipital condyles on the skull.

The axis has a protrusion called the odontoid process, also called the “dens” after its shape that resembles a tooth.  The dens articulates with the atlas and creates a pivot join which allows the head to turn left and right.

Unlike the other vertebrae, the atlas does not have a body, though it does have a large central vertebral foramen through which the spinal cord passes.