Spine · Irregular bone
Axis (C2 Vertebra)
The axis is the second vertebra of the spine. It has a peg that the atlas above pivots around, allowing you to turn your head to say "no".
What it is
The axis (C2) is the second neck vertebra, with an upward peg (the odontoid process or "dens") that the atlas rotates around.
Where it is
The upper neck, just below the atlas.
What it does
Acts as a pivot that lets the head and atlas rotate from side to side — the "no" shake of the head.
Connections
Joints and connections
- Joint with the atlas (C1) above
- Joint with the third cervical vertebra below
When things go wrong
Common injuries and conditions
- Odontoid peg fracture and "hangman's fracture" — serious upper-neck injuries
Education and reference only. This explains the anatomy in plain terms; it is not a diagnosis. A severe injury, a visibly deformed limb, or the inability to move or bear weight needs urgent assessment — call 999 or go to A&E for a serious injury.
Did you know?
An interesting fact
The peg of the axis lets your head rotate; together the atlas and axis provide much of the neck's turning movement.
Answers
Axis: frequently asked questions
What does the axis vertebra do?
The axis is the second neck vertebra. Its peg lets the head and the atlas above rotate, allowing you to turn your head side to side.
Explore the spine
Related bones
Sources
Where this is drawn from
- NHS — Anatomy and body systems
- Gray's Anatomy for Students (Drake, Vogl, Mitchell)
- TeachMeAnatomy — skeletal system
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