Which structure does NOT form a border of the bony vertebral canal?

Which structure does NOT form a border of the bony vertebral canal?

• A. Vertebral body
• B. Pedicles
• C. Laminae
• D. Disc

Answer: (D)

The walls of the bony vertebral canal are formed by parts of the vertebrae: the anterior border comes from the vertebral bodies (with the intervertebral discs between adjacent bodies helping define the boundary), the lateral aspects are formed by the pedicles, and the posterior wall is built by the laminae of the vertebral arches. The intervertebral disc itself is a cartilaginous pad between vertebral bodies, not a bone, so it does not constitute a bony border of the canal. That’s why the disc is the structure that does not form a border of the bony vertebral canal.

The walls of the bony vertebral canal are formed by parts of the vertebrae: the anterior border comes from the vertebral bodies (with the intervertebral discs between adjacent bodies helping define the boundary), the lateral aspects are formed by the pedicles, and the posterior wall is built by the laminae of the vertebral arches. The intervertebral disc itself is a cartilaginous pad between vertebral bodies, not a bone, so it does not constitute a bony border of the canal. That’s why the disc is the structure that does not form a border of the bony vertebral canal.