What does the axis superiorly articulate with?

The axis, or second cervical vertebra (C2), articulates superiorly with the atlas (C1), which is the first cervical vertebra. This joint allows for a range of motion, including the nodding of the head. The articulation between the axis and atlas is crucial for the rotation of the head and neck. Additionally, the odontoid process (dens) of the axis fits into the atlas, providing stability and support.