Kaelalülide

Kaelalülide refers to the cervical vertebrae, which are the bones that make up the neck of vertebrates. In humans, there are typically seven cervical vertebrae, numbered C1 through C7. These vertebrae are crucial for supporting the head and allowing for a wide range of motion, including nodding, turning, and tilting the head.

The uppermost cervical vertebra, C1, is known as the atlas. It lacks a vertebral body and instead has a ring-like structure that articulates with the occipital bone of the skull, allowing for the up-and-down movement of the head. The second cervical vertebra, C2, is called the axis. It possesses a prominent projection called the dens (or odontoid process) that extends upward into the atlas, enabling the rotational movement of the head.

The remaining cervical vertebrae, C3 through C7, share a more typical structure with a vertebral body, vertebral arch, and spinous processes. These vertebrae provide stability to the neck while still allowing for flexibility. The cervical spine also houses important structures like the spinal cord, arteries, and nerves that connect the brain to the rest of the body. Injuries to the cervical vertebrae can have serious consequences due to the proximity of these vital components.