![regions of the spine regions of the spine](https://www.registerednursern.com/wp-content/uploads/2020/02/vertebral-column-curves.jpg)
The Upper Cervical Spine – The Axis (C1) and the Atlas (C2) The spinous processes of the C2 to C6 vertebrae are bifid, C1 has a posterior tubercle instead of a spinous process, and C7 has a much larger and singular spinous process, known as the vertebra prominens, which is similar to those in the thoracic vertebrae. All seven cervical vertebrae have a transverse foramen within their transverse processes, where a pair of vertebral arteries travel cranially through the vertebrae starting at C6 before coursing medially over the arch of C1 towards the foramen magnum. However, the additional motion and flexibility may carry an increased risk for injury of the spinal cord and its associated neurovascular structures. Thus, an increased range of motion takes priority over vertebral size and rigidity. Large vertebral bodies are not necessary considering the relatively small weight-bearing load at this level. The main role of the cervical spine is to support and promote the movement of the head and neck. ĭespite displaying most typical vertebral hallmarks, a significant amount of anatomical variation exists within the cervical spine. In the cervical spine, the costal process becomes the anterior part of the transverse process that encloses the vertebral artery foramen. Additionally, the transverse processes and the superior and inferior articular processes are present near the junction of the pedicles and the laminae. Its main role is to protect the spinal cord and its associated vascular structures. The pedicles, laminae, and dorsum of the vertebral body form the vertebral foramen, a complete osseous ring that encloses the spinal cord. The two laminae join at the midline producing a dorsal projection called the spinous process. The dorsal arch typically consists of a pair of pedicles arising from the dorsal vertebral body, which unite dorsally by a pair of flat laminae. Each vertebral body is linked to its cranial and caudal counterparts by an intervertebral disk. The vertebral body is the main site of intervertebral articulation and load-bearing. Generally, each vertebra is comprised of a ventral vertebral body comprised of mostly trabecular cancellous and a denser, mostly cortical dorsal vertebral arch. The typical vertebrae have hallmark anatomic structures that are conserved across the cervical, thoracic, and lumbar regions. As a whole, the cervical spine is responsible for supporting the weight of the cranium and allowing motion of the head and neck. The subaxial spine includes the five most caudal cervical vertebrae (C3-C5). The CCJ includes the occiput and the two most cephalad cervical vertebrae known as the atlas (C1) and the axis (C2). The cervical spine, comprised of seven cervical vertebrae referred to as C1 to C7, is divided into two major segments: the craniocervical junction (CCJ) and the subaxial spine. Five fused vertebrae typically form the sacrum, with four forming the coccyx.
![regions of the spine regions of the spine](https://www.goodmancampbell.com/wp-content/uploads/2020/12/cervical.png)
Meanwhile, the sacrum and the coccyx are two sets of fused vertebrae at the caudal aspect of the spine that convey no motion. While somewhat similar in terms of bone morphology, these three regions variably balance spinal rigidity with flexibility and movement and articulate in a particular fashion that contributes to the overall S-shaped curvature of the spine. There are seven, twelve, and five articulating vertebrae in the cervical, thoracic, and lumbar spine. It subdivides into five regions based on curvature and morphology: the cervical, thoracic, and lumbar spine, the sacrum, and the coccyx. The spine, or vertebral column, is a segmental set of 33 bones and associated soft tissues that comprise the subcranial portion of the axial skeleton.