What is considered the axis in the cervical spine?

The cervical spine's axis refers specifically to the second cervical vertebra, known as C2. This vertebra is particularly significant because it has a unique structure, including the odontoid process or dens, which allows for a wide range of motion, including rotation of the head. The first cervical vertebra, or C1 (also called the atlas), supports the skull and allows for nodding movements, but it is the C2 that serves as the pivot point for the rotation that the neck can perform. Understanding the role of C2 as the axis in the cervical spine is crucial for grasping how the cervical spine facilitates movement and how injuries in that area can affect overall mobility and stability.