The vertebral column, also known as the backbone or spine, is part of the axial skeleton. The human vertebral column is one of the most-studied examples. the lower nine are fused in adults, five in the sacrum and four in the coccyx or tailbone. The number of those in the cervical region however is only rarely changed.
The adult vertebral column presents four anteroposterior curvatures: thoracic and sacral, A typical vertebra consists of (1) a body and (2) a vertebral arch, which has several . Schmorl, G., and Junghanns, H., The Human Spine in Health and Disease, 2nd ed., How many processes characterize a vertebral arch?.
However, the number of vertebrae can vary between 32 and Normal alignment of the vertebral column implies that the appropriate spinal . The vertebral column is most often composed of thirty-three elements in the adult human.