1 — Anterior sacral foramina; 2 — Coccyx [coccygeal vertebrae CoI-CoIV]; 3 — Sacrum [sacral vertebrae SI-SV]; 4 — Posterior sacral foramina; 5 — Lumbar vertebrae [LI-LV]; 6 — Transverse process; 7 — Thoracic vertebrae [TI-TXII]; 8 — Spinous process; 9 — Cervical vertebrae [CI-CVII]; 10 — Atlas [CI]; 11 — Axis [CII]; 12 — Vertebra prominens [CVII]; 13 — Superior costal facet; 14 — Inferior costal facet; 15 — Transverse costal facet; 16 — Superior articular process; 17 — Inferior articular process; 18 — Intervertebral foramen; 19 — Intervertebral disc;
20 — Promontory; 21 — Auricular surface
