The cervical spine is comprised of seven vertebrae: C1, C2, C3, C4, C5, C6, and C7. These vertebrae begin at the base of the skull and extend down to the thoracic spine. The cervical vertebrae have cylindrical bones that lie in front of the spinal cord and stack up one on top of the other to make one continuous column of bones in the neck.
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At each level, the vertebrae protect their segment of the spinal cord and work with muscles, tendons, ligaments, and joints to provide a combination of support, structure, and flexibility to the neck.
The cervical vertebra nearest the skull, C1, is the smallest, and then the vertebrae get bigger as they go down to C7. The lower vertebrae need to be bigger to support the extra loads from above. Similarly, all of the cervical vertebrae are smaller than the thoracic vertebrae (upper and middle back), and the largest vertebrae are in the lumbar spine, or lower back.
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Cervical vertebrae C3 through C6 are known as typical vertebrae because they share the same basic characteristics with most of the vertebrae throughout the spine. Typical vertebrae have:
C1 and C2 are considered atypical vertebrae and have some distinguishing features compared to the rest of the cervical spine.
About 50% of the head’s rotation occurs at this joint.
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The seventh cervical vertebra, also called the vertebra prominens, is considered a unique vertebra and usually has the most prominent spinous process. When feeling the back of the neck, the C7 vertebra’s bony spinous process will stick out more than the other cervical vertebrae.
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C7 is the bottom of the cervical spine and connects with the top of the thoracic spine, T1, to form the cervicothoracic junction—also referred to as C7-T1. Not only is C7’s spinous process significantly bigger than those of the vertebrae above, it’s also a different shape to better fit with T1 below.
Due to its larger size and key location at the cervicothoracic junction, several more muscles connect to C7’s spinous process compared to other cervical vertebrae.
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The joints of Luschka, also known as uncovertebral joints, are found between vertebral segments from C3 down to C7.
These joints are comprised of two uncinate processes—one rising up from the top of each side of the vertebral body—that fit in indentations in the vertebral body above. The joints of Luschka help with the neck’s forward and backward movements while also limiting the bending to either side.
The joints of Luschka are relatively small compared to the facet joints. Also, unlike the facet joints, the joints of Luschka are not present at birth. Typically, the joints of Luschka develop by age 10.
For the most part, the cervical vertebrae are extremely durable and resistant to injury. Most neck pain relating to the cervical vertebrae is the result of wear and tear, not an injury.
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