Kaelaketid

Kaelaketid are the bones that form the cervical portion of the vertebral column. In humans, the neck region comprises seven vertebrae, labeled C1 through C7. The first vertebra, C1 (atlas), supports the skull and lacks a true vertebral body; the second, C2 (axis), carries the odontoid process (dens) that functions as a pivot for rotation. C3 through C7 are typical cervical vertebrae with a body, a vertebral arch, a spinous process, and transverse processes that contain openings for the passage of the vertebral arteries.

Intervertebral discs separate adjacent kaelaketid and contribute to their flexibility. The upper cervical joints, including the atlanto-occipital and atlanto-axial joints, enable much of the head’s movement, particularly rotation. The remaining cervical vertebrae provide stability and support while allowing flexion, extension, lateral bending, and rotation. The spinal cord runs through the vertebral foramina, and the cervical region houses major neural and vascular structures that supply the head and upper limbs.

Development and variation: the kaelaketid arise from the somites during embryonic development and undergo gradual ossification and, in many components, partial fusion during growth. Most adults have seven cervical vertebrae, though anatomical variations can occur.

Clinical relevance: injuries such as cervical fractures, whiplash, or degenerative changes like cervical spondylosis can affect kaelaketid and surrounding tissues. Imaging methods including X-ray, computed tomography (CT), and magnetic resonance imaging (MRI) are used to assess alignment, stability, and pathology.

Etymology and context: kaelaketid translates as “neck bones” in Estonian, typically referring to the cervical vertebrae. See also cervical spine, atlas, axis, vertebral column.