A vertebra (plural: vertebrae) is a fundamental bony unit of the spine. Vertebrae within one region of the spine appear slightly different than in the other. They vary in size and present distinct features. However, all vertebrae also have some common characteristics. A typical vertebra has a vertebral body, vertebral arch and several projections.
- The vertebral body is the large cylindrical-shaped anterior part of a vertebra. It serves as the weight-bearing structure. Therefore, the size of each next vertebral body increases to better support the upper body weight. Two adjacent vertebral bodies are separated by a fibrocartilaginous intervertebral disc.
- The vertebral arch forms the lateral and posterior portions of a vertebra. It is composed of paired pedicles and laminae. Both pedicles anchor the vertebral arch to the posterior surface of the vertebral body. Posterior to the pedicles are two bony plates called laminae that merge in the midline of the arch and connect the transverse and spinous processes of a vertebra.
The superior and inferior aspects of the pedicles contain superior and inferior vertebral notches. The inferior vertebral notch is larger than the superior one. Notches of adjacent vertebrae align and form intervertebral foramina that transmit the spinal nerves.