Cervical Vertebrae

The cervical vertebral bodies are smaller than those of the other movable vertebrae and increase in size from above downward; they are broader in the transverse diameter than anteroposteriorly. The superior body surfaces are concave from side to side and slightly convex from front to back, whereas the inferior surfaces are reciprocally curved or saddle shaped. The lateral edges of the superior body surface are raised, whereas those of the lower surface are beveled, and small clefts exist between them. Some claim these are miniature synovial joints, but others believe they are merely spaces in the lateral parts of the corresponding intervertebral disks.

The vertebral foramina are comparatively large in order to accommodate the cervical enlargement of the spinal cord; they are bounded by the bodies, pedicles, and laminae of the vertebrae. The pedicles project posterolaterally from the bodies and are grooved by superior and inferior vertebral notches of almost equal depth, which form the intervertebral foramina by connecting with similar notches on adjacent vertebrae. The medially directed laminae are thin and relatively long and fuse posteriorly to form short, bifid spinous processes. Projecting laterally from the junction of the pedicles and laminae are articular pillars supporting superior and inferior articular facets.

Each transverse process is pierced by a foramen, bounded by narrow bony bars ending in anterior and posterior tubercles; these are interconnected lateral to the foramen by the so-called costotransverse bar. Only the medial part of the posterior bar represents the true transverse process; the anterior and costotransverse bars and the lateral portion of the posterior bar constitute the costal element. These elements, especially in the seventh and/or sixth cervical vertebrae, may develop abnormally to form cervical ribs. The upper surfaces of the costotransverse bars are grooved and lodge the anterior primary rami of the spinal nerves. The anterior tubercles of the sixth cervical vertebra are large and are termed the carotid tubercles because the common carotid arteries lie just anteriorly and can be compressed against them.

The seventh cervical vertebra is called the vertebra prominens because its spinous process is long and ends in a tubercle that is easily palpable at the lower end of the nuchal furrow; the spinous process of the first thoracic vertebra is just as prominent. The seventh cervical vertebra sometimes lacks a transverse foramen on one or both sides; when present, the foramina transmit only small accessory vertebral veins.

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