Presentation of the Vertebral Column of the Axial Skeleton.

1. Axial Skeleton The Vertebral Column

2. The Vertebral Column Extends from skull (supports the skull) to the pelvis (distributes weight to lower limbs) Five sections: cervical, thoracic, lumbar, sacrum, coccyx Born with 33 vertebrae, but nine fuse into two bones (sacrum and coccyx) Vertebrae separated by intervertebral discs

3. The Vertebral Column – VertebraeStructure Body/Centrum – disc-like part facing anteriorly Vertebral arch – formed by joining of all posterior extensions of vertebra Vertebral foramen – opening which spinal cord passes Transverse processes – two lateral projections from arch Spinous process – projection from posterior of arch Articular processes – superior and inferior projections lateral to foramen that articulate with above vertebra

4. The Vertebral Column – Vertebrae Structure

5. The Vertebral Column – Cervical Vertebrae 7 vertebrae (identified as C1 to C7) First two vertebrae are Atlas (C1) and Axis (C2) Allow for the movement/rotation of skull Do not have a body Atlas articulates with the occipital condyles of the skull C3 through C7 are remaining cervical vertebrae Smallest vertebrae Contain transverse foramen Spinous processes usually split in middle

6. The Vertebral Column – Cervical Vertebrae

7. The Vertebral Column – Thoracic Vertebrae 12 vertebrae (identified as T1 to T12) Connected with ribs Typical shape, slightly modified for ribs Includes costal facets to articulate with ribs in posterior Spinous process long, pointed down

8. The Vertebral Column – Thoracic Vertebrae

9. The Vertebral Column – Lumbar Vertebrae 5 vertebrae (identified as L1 to L5) Bulkier shape Hatchet-shaped spinous processes Receives most of stress on vertebral column

10. The Vertebral Column – Lumbar Vertebrae

11. The Vertebral Column – Sacrum and Coccyx Sacrum is inferior to the L5 vertebra and superior to the coccyx Formed from the fusion of five vertebrae Alae are winglike projections that articulate laterally with the hip bones Forms posterior wall of pelvis Includes median sacral crest and dorsal sacral foramina Coccyx is inferior to sacrum Formed from fusion of three to five tiny vertebrae Commonly called the “tailbone”

12. The Vertebral Column – Sacrum and Coccyx