C1 (Atlas) - 1st Cervical Vertebra

[Continued from above] . . . as the god Atlas upheld the world. The cranium's occipital condyles are seated and articulate on the C1 vertebra's lateral masses for vertical articulation of the head (nodding). As with the other cervical vertebrae, the C1 vertebra is among the smallest of the true vertebrae, occupying the neck and lying above the thoracic vertebrae. The C1, uniquely, lacks a ventral body or centrum, as it is fused with that of the C2 vertebra at its own odontoid peg together with the odontoid process or dens of the C2 axis vertebra. Only an anterior arch, a thin stretch of bone, crosses the spinal column where the centrum would exist in another vertebra. However, its transverse processes are quite large. Two oblique transverse foramen permit the passage of nerves, vertebral artery, and the vertebral vein away from the spinal cord - which passes through a large vertebral foramen, protecting the brain stem - and out to the body.