What structure do the vertebral laminae unite to form posteriorly?

• A. Vertebral arch
• B. Spinous process
• C. Transverse process
• D. Vertebral body

Answer: (B)

The posterior portion of the vertebra is formed by the vertebral laminae uniting to create the spinous process. The spinous process is a bony projection that extends posteriorly from the vertebral arch and can be felt as a prominent structure along the midline of the back. It serves various purposes, including providing attachment for muscles and ligaments, as well as playing a role in the movement and stability of the vertebral column.

The vertebral arch consists of the laminae and pedicles, but it is the fusion of the laminae specifically that leads to the formation of the spinous process. While the vertebral body is the largest part of the vertebra located anteriorly, and the transverse processes are lateral projections from the vertebra, neither of these structures is formed by the union of the laminae.