1 — Posterior tubercle; 2 — Longitudinal bands; 3 — Lateral mass; 4 — Foramen transversarium; 5 — Transverse process; 6 — Superior articular facet; 7 — Median atlanto-axial joint; 8 — Anterior tubercle; 9 — Alar ligaments; 10 — Apical ligament of dens; 11 — Transverse ligament of atlas; 12 — Dens axis [CII]; 13 -Vertebral foramen; 14 — Posterior arch; 15 — Spinous process
