The structure indicated is the vertebral body.
There are 33 vertebrae which make up the spinal column:
- 7 cervical
- 12 thoracic
- 5 lumbar
- 5 fused sacral vertebrae
- 3-4 fused coccygeal vertebrae
The typical vertebra consists of the following features:
- Vertebral body
- Vertebral arch (neural arch) consisting of lamina and pedicle
- Spinous process
- Transverse process
- Vertebral foramen (collectively form vertebral canal)
- Superior and inferior articular processes
- Superior and inferior vertebral notches
The vertebral body is the largest component of the vertebra. Between adjacent vertebrae within the spinal cord, the vertebral bodies are joined by intervertebral discs which form fibrocartilaginous joints and provide support and shock absorption for the spinal column.
Learn more about the anatomy of the vertebrae in this tutorial.