This site is intended for healthcare professionals

Go to /sign-in page

You can view 5 more pages before signing in

Atlas

Last reviewed dd mmm yyyy. Last edited dd mmm yyyy

Authoring team

The atlas is the most superior cervical vertebra. It supports the skull and is named after a character in Greek mythology who supported the earth on his shoulders. It exhibits little resemblance to other vertebrae:

  • ring-shaped
  • vertebral body is lost in development to the immediately inferior vertebra, the axis, where it forms the odontoid peg or dens
  • vertebral foramen:
    • more oval than the rest of cervical vertebrae
    • consists of anterior and posterior arches joined by lateral masses on each side
  • anterior arch:
    • shorter and straighter than posterior arch
    • connects lateral mass on each side to median anterior tubercle on its anterior surface
    • posterior to anterior tubercle on the surface of atlas facing vertebral canal is a facet for articulation with the dens of the axis
  • posterior arch represents pedicles and laminae of typical cervical vertebra:
    • connects lateral mass on each side to median posterior spinous tubercle; spinous process does not develop
    • close to lateral mass on superior surface is groove for vertebral artery as it passes to foramen magnum
  • lateral mass: junction of anterior and posterior arches
    • medial small tubercle for attachment to atlas ligament
    • has superior & inferior articular facets
  • superior articular facets:
    • articulate with condylar process of occipital bone
    • kidney-shaped and concave
  • inferior articular facets:
    • round and less concave than superior facets
    • articulate with axis
  • transverse process: broad, strong, occasionally bifid
    • represents posterior tubercle of other vertebrae
  • foramen transversarium: within the transverse process, it transmits vertebral vessels and sympathetic nerves

Related pages

Create an account to add page annotations

Add information to this page that would be handy to have on hand during a consultation, such as a web address or phone number. This information will always be displayed when you visit this page

The content herein is provided for informational purposes and does not replace the need to apply professional clinical judgement when diagnosing or treating any medical condition. A licensed medical practitioner should be consulted for diagnosis and treatment of any and all medical conditions.

Connect

Copyright 2024 Oxbridge Solutions Limited, a subsidiary of OmniaMed Communications Limited. All rights reserved. Any distribution or duplication of the information contained herein is strictly prohibited. Oxbridge Solutions receives funding from advertising but maintains editorial independence.