The biggest differences between the vertebrae in the spine, are shape and secondary functionality. The cervical vertebrae are the smallest, they are the most flexible allowing the biggest range of head movement. The only vertebra containing no vertebral body, the axis, is located in the cervical vertebrae. Thoracic vertebrae are mid sized, and the physical shape of the thoracic vertebrae are the most rigid because they connect the ribcage and torso to the spine. Thoracic vertebrae are the only vertebrae to aid in protecting the inner organs. Lumbar Vertebrae are the largest spinal bones, their size aids in supporting the majority of upper body weight, and allows for twisting and bending.
Intervertebral discs are shock absorbing cartilage in