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Vertebrae, together with intervertebral discs, compose the vertebral column or spine. The spine extends from the skull to the coccyx and comprises the cervical, thoracic, lumbar, and sacral regions. Major functions include protection of the spinal cord and branching spinal nerves, support for the thorax and abdomen, and facilitation of flexibility and mobility. Intervertebral discs confer mobility while maintaining the structural integrity of the vertebral column. The cervical region contains 7 vertebrae, C1 to C7, the smallest within the vertebral column. Intervertebral discs, laminae, and articular processes of adjacent vertebrae form spaces through which spinal nerves exit. The intervertebral foramen is bounded anteriorly by vertebral bodies and discs, superiorly and inferiorly by pedicles, and posteriorly by facet joints, capsules, and the ligamentum flavum. The lamina is not typically considered a primary boundary. Cervical vertebrae collectively generate a lordotic curve. Although vertebrae share general morphologic features, several distinctive characteristics are present in the cervical region (see Image. Comparative Anatomy of Typical and Atypical Cervical Vertebrae).[1] A typical vertebra consists of a vertebral body, a vertebral arch, and 7 processes. The vertebral body bears the majority of axial load and increases in size from superior to inferior. The body comprises trabecular bone containing red marrow, surrounded by a thin layer of compact bone. The vertebral arch, together with the posterior aspect of the body, forms the vertebral (spinal) canal, which houses the spinal cord (see Image. Cervical Spine Magnetic Resonance Imaging in Multiple Views). The arch includes bilateral pedicles, cylindrical bone structures connecting the arch to the body, and bilateral laminae, flat bone segments forming most of the arch and connecting the transverse and spinous processes (see Image. Computed Tomography Anatomy of the Cervical Vertebrae).

A typical vertebra consists of a vertebral body, a vertebral arch, and 7 processes. The vertebral body bears the majority of axial load and increases in size from superior to inferior. The body comprises trabecular bone containing red marrow, surrounded by a thin layer of compact bone. The vertebral arch, together with the posterior aspect of the body, forms the vertebral (spinal) canal, which houses the spinal cord (see Image. Cervical Spine Magnetic Resonance Imaging in Multiple Views). The arch includes bilateral pedicles, cylindrical bone structures connecting the arch to the body, and bilateral laminae, flat bone segments forming most of the arch and connecting the transverse and spinous processes (see Image. Computed Tomography Anatomy of the Cervical Vertebrae). Each vertebra contains 4 articular processes—2 superior and 2 inferior—that articulate with the inferior and superior articular processes of adjacent vertebrae, respectively. The junction of superior and inferior articular facets forms a facet, or zygapophyseal, joint. These joints maintain vertebral alignment, regulate the range of motion, and bear weight in certain positions. The spinous process projects posteriorly and often inferiorly from the vertebral arch, overlapping the inferior vertebra to variable degrees, depending on the spinal region. Two transverse processes extend laterally from the vertebral arch symmetrically. Typical cervical vertebrae exhibit several features distinct from thoracic and lumbar vertebrae. The most notable distinction is the presence of a transverse foramen in each transverse process. These foramina encircle the vertebral arteries and veins. In most individuals, the vertebral artery enters the transverse foramen at C6 and ascends through C6 to C1. Variants include entry at other levels, such as C5 or C7. The C7 transverse foramen frequently transmits a vein and sympathetic plexus rather than the artery, although this pattern is not universal.

Typical cervical vertebrae exhibit several features distinct from thoracic and lumbar vertebrae. The most notable distinction is the presence of a transverse foramen in each transverse process. These foramina encircle the vertebral arteries and veins. In most individuals, the vertebral artery enters the transverse foramen at C6 and ascends through C6 to C1. Variants include entry at other levels, such as C5 or C7. The C7 transverse foramen frequently transmits a vein and sympathetic plexus rather than the artery, although this pattern is not universal. Another feature unique to cervical vertebrae is the bifid spinous process, which may increase the surface area available for muscle attachment (see Physiologic Variants). Spinous process length increases progressively from superior to inferior cervical vertebrae. Superior articular facets of cervical vertebrae generally face posteriorly, although studies indicate that more inferior vertebrae may have superior facets oriented posterolaterally, resembling thoracic vertebrae. Cervical vertebrae also demonstrate the greatest relative disc height, defined as the disc height-to-vertebral body height ratio, contributing to an increased range of motion. Three atypical vertebrae are present in the cervical region. These atypical vertebrae include C1, C2, and C7. C1, also referred to as the "atlas," is unique among all vertebrae in lacking both a vertebral body and a spinous process. The relatively circular bone contains 2 bilateral masses that function in load-bearing in place of a body. Superior articular facets of these masses articulate with the occipital condyles of the skull, and inferior facets articulate with the superior facets of C2. C2, also called the "axis," is characterized by bilateral masses for articulation with C1, a vertebral body transmitting weight to C3 and inferior vertebrae, and an odontoid process, or dens, projecting from the superior aspect of the body. The dens articulates with the posterior surface of the anterior arch of C1. C7 may be classified as typical or atypical and exhibits 2 distinguishing features. First, the vertebral artery typically does not traverse the transverse foramen. Second, C7 possesses a long spinous process, termed "vertebra prominens."[2]