Q.The joint between the atlas and the axis vertebrae, which allows the head to rotate from side to side, is an example of which type of synovial joint?

[!TLDR]

The atlas-axis joint is a pivot joint, allowing rotational movement of t …

The atlas (the first cervical vertebra, supporting the skull) and the axis (the second cervical vertebra) meet at a synovial joint shaped so that the atlas, carrying the skull, can rotate around a peg-like projection of the axis. This rotational movement -- the kind that lets the head turn from side to side, as in shaking the head 'no' -- is the defining feature of a pivot joint. A hinge joint (like the elbow) permits back-and-forth movement in one p …

Recall that 'rotation of the head' is the classic, named example of a pivot joint, located …

Confusing the pivot joint (atlas-axis, pure rotation) with the hinge joint (elbow/knee, one-pla …