10/13/2026
Most vertebrae stack with a disc for cushion. Two of them don't.
The atlas sits right under your skull with no disc at all, built to let your head tilt forward and back for a nod. Just below it, the axis has a bony peg the atlas rotates around, which is what lets your head turn side to side for a shake.
Two bones doing a job the other 24 in your spine don't.
Follow along for more quick spine facts.
Find more spine health resources at spinehealth.org.