Gesturing "No" with the Head Depends on the Structure(s) of Which

Question

Gesturing "no" with the head depends on the structure(s) of which cervical vertebrae?
A) atlas
B) axis
C) vertebra prominens
D) both the atlas and the axis
E) both the atlas and the vertebra prominens

Accepted Answer

Gesturing "no" with the head involves rotation of the head around the axis joint between the atlas (C1) and the axis (C2) vertebrae. Both vertebrae are necessary for this movement, making D the best choice. The vertebra prominens (C7) is the most prominent cervical vertebra and does not contribute to this movement. The atlas also contributes to nodding, while C7 is involved in tilting the head back.