Question

which of the following is only found on the axis vertebra?

a transverseforamen
b spinousprocess
c dens (odontoidprocess)
d vertebral arch
e superior articularfacet

Explanation:

Identify the target vertebra

The question asks for a feature found only on the axis vertebra (the second cervical vertebra, or C2). We will evaluate each option based on Vertebral Column Anatomy.

Evaluate the anatomical options

• Transverse foramen: Found on all cervical vertebrae (C1–C7), not unique to C2.
• Spinous process: Found on most vertebrae (C2–S1), not unique to C2.
• Dens (odontoid process): A prominent, tooth-like projection pointing superiorly. This is a unique feature found exclusively on the axis (C2) to articulate with the atlas (C1).
• Vertebral arch: A standard structural component of almost all vertebrae, not unique to C2.
• Superior articular facet: Found on all vertebrae to allow articulation with the vertebra above, not unique to C2.

Determine the correct choice

The dens (odontoid process) is the defining characteristic unique to the axis (C2) vertebra.

Answer:

• A Transverseforamen
• B Spinousprocess
• C Dens (odontoidprocess) (Correct answer)
• D Vertebral arch
• E Superior articularfacet