Axis or C2 Vertebra, Superior View

Description

Viewed from superior, the axis (C2, epistropheus) centers the dens (odontoid process) projecting upward from the vertebral body, with its rounded apical and anterior articular surface oriented toward the anterior arch of the atlas. Flanking the dens, the paired superior articular facets sit posterolateral to the vertebral body and face superiorly to receive the inferior facets of C1. Posterior elements are arranged behind this complex, with the laminae converging toward a bifid spinous process and the transverse processes extending laterally toward the transverse foramina. Clear midline anatomy. This perspective matters because the dens is the mechanical pivot for atlanto-axial rotation, and its articular relationships explain both normal head turning and common instability patterns. Odontoid fractures (Type I-III), atlanto-axial subluxation in rheumatoid arthritis, and congenital dens anomalies all hinge on the integrity of the dens, the atlantal ring, and the stabilizing transverse ligament. Surgeons and radiologists also rely on these landmarks when correlating with open-mouth odontoid radiographs and axial CT to assess lateral mass symmetry and C1-C2 alignment. Use this illustration to teach upper cervical osteology in gross anatomy, neuroanatomy, and spine modules where students confuse atlas and axis, or to support figure plates in orthopedic, neurosurgical, and radiology publications discussing odontoid fracture classification and atlanto-axial instability. It also fits clinical patient education materials explaining why C1-C2 injuries can threaten the cervicomedullary junction despite limited bony displacement. Anatomical accuracy verified by SciePro's Medical Advisory Board.