Vertebra

Any of thirty-three ring-shaped structures that form the vertebral column which surrounds and protects the spinal cord. Each vertebra consists of a bony body with its superior and inferior articular surfaces covered by hyaline cartilage. The body includes the centrum anteriorly and vertebral arch posteriorly. The articular surfaces of the vertebrae are connected by a fibrocartilaginous intervertebral disc.

Source: NCI Thesaurus (C12933).