The C7 Vertebra

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The 7th cervical (C7) vertebra is the largest and most inferior vertebra in the neck region. Unlike the other cervical vertebrae, the C7 has a large spinous process that protrudes posteriorly toward the skin at the back of the neck. This spinous process can be easily seen and felt at the base of the neck, making it a prominent landmark of the skeleton and giving the C7 the name vertebra prominens.

The C7 is located in the spinal column inferior to the 6th cervical (C6) vertebra and superior to the first thoracic (T1) vertebra. As the transitional vertebra between the cervical and thoracic regions, the C7 has some features of both the cervical and thoracic vertebrae. Like the C3 through C6 vertebrae, C7 has a thicker area of bone called the body, located anterior to the vertebral foramen. The body of C7 supports the collective weight of the head and neck. Facets lateral to the C7's body allow the C7 to form joints with the C6 vertebra above it and the T1 below it. Fibrocartilaginous disks above and below the C7's body provide cushioning. The facets and disks surrounding the body provide both stability and flexibility to the neck.

Posterior to the body is a thin ring of bone known as the vertebral arch. The vertebral arch surrounds the hollow vertebral foramen and provides muscle attachment sites to the C7 vertebra. Delicate tissues, including the spinal cord and nerves, pass through the vertebral foramen and are protected by the vertebral arch. Extending from both lateral sides of the vertebral arch are the transverse processes and their tiny, hollow transverse foramina. Each transverse foramen provides a conduit for nerves and the vertebral arteries and veins that supply blood to tissues of the head and neck.

Several bony processes extend from the vertebral arch and provide important muscle attachment sites for the muscles of the neck. On both lateral sides of C7, the transverse processes provide insertion points for the erector spinae muscles that extend and flex the neck. The spinous process extends from the posterior of the vertebral arch to provide connection points for the muscles that extend the neck, including the trapezius and spinalis muscles. Unlike the notched spinous processes of the C3-C6 vertebrae, the vertebra prominens resembles the T1 vertebra with a spinous process that is large, straight, and flattened at the end. The end of the nuchal ligament, which supports the muscles of the neck and connects the occipital bone of the skull to the C7 vertebra, attaches at the tip of the spinous process.