Axis (C2 Vertebra)

Description

Centered on the axis (C2) in close anatomical detail, the dens (odontoid process) rises superiorly from the vertebral body and sits anterior to the vertebral foramen, where it normally articulates with the anterior arch of the atlas (C1). Laterally, the transverse processes extend from the vertebral arch and contain paired transverse foramina, positioned anterolateral to the vertebral foramen along the root of each process. Blue-tinted articular cartilage marks the superior articular facets that face superolaterally toward C1, while the inferior facets orient inferolaterally to meet C3. A cortical shell surrounds cancellous bone in section. Rotation happens here. The dens functions as the pivot for the median atlanto-axial joint, and its relationship to the spinal canal explains why displaced odontoid fractures, or atlanto-axial instability in inflammatory arthropathies, can threaten the upper cervical spinal cord. The transverse foramina are more than a cervical hallmark, they define the corridor for the vertebral artery and venous plexus, a point of practical relevance during posterior approaches and lateral mass instrumentation. Small offsets in facet orientation matter for coupled motion and for interpreting CT of the upper cervical spine. Ideal for gross anatomy and musculoskeletal modules covering the cervical spine, this asset also fits radiology teaching files when paired with axial CT or CTA discussions of the vertebral artery at C2 and trauma patterns such as Anderson-D’Alonzo odontoid fractures. Spine surgeons and medical-legal teams will appreciate the clean depiction of articular surfaces and canal boundaries when illustrating atlanto-axial biomechanics and injury mechanisms. Anatomical accuracy verified by SciePro's Medical Advisory Board.