Posterior Arch of Atlas

Description

The posterior arch is the curved, posteromedially located part of the atlas (first cervical vertebra). It is the longer of the two arches of the atlas, the other being the anterior arch. The posterior arch:

—is continuous anterolaterally with both the right and left lateral masses of atlas;

—consists of the posterior tubercle of atlas and both the right and left grooves for vertebral arteries;

—provides origin sites for both the right and left rectus capitis posterior minor muscles;

—provides attachment sites for the nuchal ligament, ligamenta flava and posterior atlantooccipital membrane.