Cervical Vertebrae
This article focuses on the typical cervical vertebrae (C3-C7)
Regions
The typical cervical vertebrae are C3 to C7. The transition zone is centred on C2, and so the upper transition zone refers to the atlantoaxial joint, and the lower transition zone refers to the C2-C3 joint. The suboccipital zone is centred on C1.
The cervical spine can also be divided into the upper occipito-atlanto-axial joint complex, and the sub-axial spine.
- Upper occipito-atlanto-axial joint complex
- Multiple synovial joints with strong transverse and alar ligaments provide about half of total movements
- Movements: C0-1 - nutation, C1-2 - rotation
- Nerve roots: C1 nerve sits under the vertebral artery, C2 nerve root sits with veins.
- They are well preserved in older subjects
- Sub-axial spine; discs, and zygapophyseal joints.
- Uncovertebral clefts
- 45 degree facet joints, allows for flexion and extension but not much rotation
- Oblique, antero-lateral course of nerve roots
- Vertebral arteries in foramina transversaria.
- Small anterior muscles, large posterior muscles. Therefore vulnerable to extension trauma.
Suboccipital Zone
- Main article: Atlanto-occipital Joint
Upper Transition Zone
- Main article: Atlanto-axial Joint
Lower Transition Zone
The lower half of the axis (C2) vertebra has a typical cervical vertebra structure. There is a vertebral body centrally, and paired inferior articular processes laterally. The upper half receives the paired lateral masses of the atlas (C1), and the load is transmitted down the cervical spine through an anterior channel (vertebral bodies) and a posterior channel (the paired zygapophyseal joints). The load is approximately split equally between these two channels.
Typical Cervical Vertebrae
The typical cervical consists of a vertebral body and paired articular pillars. There are also transverse processes that come outwards from the articular pillars. The laminae are formed posteriorly by two pillars, and there is a spinous process in the middle.
