The Vertebral Column and Vertebrae

The vertebral column is a chain of bones divided into five regions – cervical (C1-C7), thoracic (T1-T12), lumbar (L1-L5), sacral (S1-S5), and coccygeal (4, the lower 3 are commonly fused to form the coccyx). The intervertebral disks are flexible cartilaginous structures that lie between adjacent vertebrae.