Vertebra C1
Vertebra CI
- Related terms: C1
Definition
1st cervical vertebra
The first cervical vertebra C1, (atlas (C1)), is a unique ring-shaped structure that plays a crucial role in supporting the skull and facilitating its range of motion. The atlas lacks a vertebral body and a spinous process, distinguishing it from other cervical vertebrae.
Anatomically, the atlas consists of an anterior arch, a posterior arch, and two lateral masses. The anterior arch features an anterior tubercle and a facet for articulation with the odontoid process (dens) of the axis (C2). The posterior arch includes a posterior tubercle and a groove for the vertebral artery. The lateral masses contain the superior articular facets, which are concave and articulate with the occipital condyles of the skull, allowing for the nodding motion of the head. The inferior articular facets are flat and articulate with the axis, facilitating rotation.
The transverse processes of the atlas are prominent and contain the transverse foramina, which transmit the vertebral arteries. The neural canal of the atlas is large and oval, accommodating the spinal cord and the dens of the axis.
References
1.Comparative Anatomy and 3D Geometric Morphometrics of the El Sidrón Atlases (C1).Palancar CA, Torres-Tamayo N, García-Martínez D, et al.Journal of Human Evolution. 2020;149:102897. doi:10.1016/j.jhevol.2020.102897.
2.Anatomical and Computed Tomographic Analysis of C1 Vertebra.Naderi S, Cakmakçi H, Acar F, et al.Clinical Neurology and Neurosurgery. 2003;105(4):245-8. doi:10.1016/s0303-8467(03)00037-4.
3.Developmental Morphology and Ossification Patterns of the C1 Vertebra.Rao RD, Tang S, Lim C, Yoganandan N.The Journal of Bone and Joint Surgery. American Volume. 2013;95(17):e1241-7. doi:10.2106/JBJS.L.01035.
4.C1 Anatomy and Dimensions Relative to Lateral Mass Screw Placement.Christensen DM, Eastlack RK, Lynch JJ, Yaszemski MJ, Currier BL.Spine. 2007;32(8):844-8. doi:10.1097/01.brs.0000259833.02179.c0.
