Cervical Spine: Structure, Function & Diseases

The cervical spine is the most mobile section of the spine. Whiplash, in which soft tissues of the cervical spine are damaged as a result of a rear-end collision, is the best-known impairment of this spinal segment.

What is the cervical spine?

Schematic anatomical representation of the spine and its structure. The cervical spine (CS) represents the most mobile segment of the columna vertebralis (spinal column), consisting of seven cervical vertebrae (vertebrae cervicales), which connects the skull (cranium) to the trunk. The vertebrae cervicales form a stable row in which the individual adjacent cervical vertebrae are connected to each other by means of paired vertebral joints. To improve mobility, there are intervertebral discs between the individual vertebrae cervicales that buffer axial force effects. To ensure mobility as well as stability, a variety of muscles and ligaments also run between the vertebrae of the cervical spine.

Anatomy and structure

The cervical spine is composed of a total of seven vertebrae cervicales. While the five lower cervical vertebrae are largely the same in terms of their structure, the two upper ones have a different, divergent structure. The uppermost, first cervical vertebra, the so-called atlas, serves as the transition from the cranium to the trunk. In its area, the cerebral structures pass into the spinal canal (canalis vertebralis) as the spinal cord. Cranially (skullward), the atlas and os occipitale (flat cranial bone, occipital bone) form the paired antlantooccipital joint (first head joint). The adjacent, second cervical vertebra (axis) also has an anterior peg, called the dens axis, which projects into the atlas ring. The axis and atlas also form the antlantoaxial joint (second cervical joint). The vertebrae cervicales each consist of a corpus vertebrae (vertebral body), an arcus vertebrae (vertebral arch), four smaller joints, a processus spinosus (dorsal spinous process), a transverse process, and a foramen vertebrae (vertebral hole formed by the vertebral arch). The foramina of all vertebrae of the spine form the bony spinal canal through which the spinal cord passes.

Function and tasks

As a static structure, the cervical spine primarily supports the skull, in whose movements it participates in interaction with its muscular and ligamentous apparatus. The smallest functional unit is called a motion segment, which is an association of joints, ligaments, muscles and intervertebral discs formed between two adjacent vertebrae. The overall range of motion results from the addition of the relatively small ranges of motion between the individual cervical vertebrae, with the lower sections of the cervical spine in particular exhibiting a higher range of motion. The comparatively large range of motion of the cervical spine is primarily provided by the largely horizontally aligned vertebral joints. For example, the antlantooccipital joint, formed by the atlas together with the os occipitale, acts as an ellipsoid or ovoid joint to allow the skull to move, especially flexion and extension (pitching movements). In addition, the atlas and axis form the so-called antlantoaxial joint, which is primarily responsible for the rotational movements of the skull. The two upper cervical joints provide very fine gradations of head movement. In addition, rotation (turning), flexion and inclination (ventral flexion), reclination (dorsal inclination) and dorsiflexion (dorsal flexion) as well as lateral flexion (sideways flexion) are possible in the cervical spine. Furthermore, the cervical spine acts as a conduit and protective structure for the spinal cord, which in turn can be understood as an extension of the cerebral system.

Diseases and disorders

Pain symptoms in the cervical spine are very common and may be manifested by torticollis and an oblique relieving posture. If the pain cannot be attributed to a specific cause, it is referred to as a non-specific cervical spine syndrome. Degenerative changes in the structures of the cervical spine can lead to a herniated disc, osteochondrosis (worn disc) or, in the case of pronounced degeneration, to facet syndrome, spondylolisthesis and spinal canal stenosis (narrowing of the cervical spine) with cervical myelopathy (damage to the spinal cord).Stress-related muscular tension can also occur, causing pain in the neck and cervical vertebrae. Damage to the soft tissue, joint capsule and/or ligamentous apparatus in the cervical spine caused by hyperflexion or hyperextension is referred to as a cervical spine distortion (also whiplash injury or whiplash injury). Depending on the severity, a cervical spine distortion may be accompanied by headaches, neck pain, limited range of motion and pain in the cervical spine area, and a feeling of head being held up. If there are concomitant swallowing difficulties, a retropharyngeal hematoma may also be present. Fractures and dislocations of the cervical spine are often associated with an increased risk of parallel injuries of the cervical medulla with (in)complete paraplegic symptoms or a lethal course. As a rule, atlas, axis and dens fractures as well as fractures of the lower cervical vertebrae are manifested by pain, a feeling of instability in the neck and/or neurological deficits, although stable cervical spine fractures can also be partially asymptomatic. In addition, isolated impairments of the cervical spine can in many cases be attributed to damage or dysfunction of individual motion segments (including herniated disc, blockage).