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Abstract The vertebral column is a flexible structure made up of bony vertebrae separated by fibrocartilagineous discs.The vertebrae are arranged in the following groups: 7 cervical, 12 thoracic, 5 lumber, 5 sacral (fused to form the sacrum) and 4 coccygeal (the lower 3 are commonly fused) .The vertebral column has four curves. The thoracic and sacral are primary and concave anteriorly, while the cervical and lumber are secondary and concave posteriorly, when the spine is full flexed, cervical and lumbar curves are obliterated.In supine position, the third lumber is the highest point of the lumbar curve while the fifth thoracic is the lowest point of the dorsal curve.A typical vertebra consists of the body anteriorly and the vertebral arch posteriorly attached to the body via the pedicles. At the junction of the pedicles and the vertebral arch or laminae, are the transverse processes. The dorsal extension of the fused laminae is the spinous process. The two pedicles are short and projecting back from the body at the junction between its lateral and dorsal surfaces, and nearer to the superior surface, so that the concavity above the pedicle is shallower than the one below it. These concavities are the vertebral notches which form the intervertebral foraminae transmitting the spinal nerves and blood vessels. |