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3D OSTEOLOGY
3D VERTEBRAL COLUMN

ATLAS (C1) ANATOMY

Atlas C1 vertebra anatomy 360-degree interactive viewer showing ring-like structure, lateral masses, anterior arch, and posterior arch

Atlas (C1) - General Structure, Preview from the app. Download 3D OSTEOLOGY for full 3D control—multiple views, x-ray mode, and unlimited zoom.

TABLE OF CONTENTS

GENERAL CHARACTERISTICS

  • The first cervical vertebra, known as the atlas, supports the head
  • Unique structure — lacks both a vertebral body and a spinous process
  • Ring-like structure composed of:
    • Anterior arch
    • Posterior arch
    • Two lateral masses

LATERAL MASS

Atlas lateral mass 360-degree viewer showing superior and inferior articular surfaces with weight-bearing structures

Atlas - Lateral Mass, Preview from the app. Download 3D OSTEOLOGY for full 3D control—multiple views, x-ray mode, and unlimited zoom.

  • Comprises about one-fifth of the atlas' ring
  • Supports the weight of the head

Superior Articular Surface

  • Large, oval, concave facets converging anteriorly and diverging posteriorly
  • Oriented upwards, medially, and slightly backwards for articulation with occipital condyles

Inferior Articular Surface

  • Nearly circular, flat or slightly convex
  • Oriented downwards and medially
  • Forms joints with the axis' (C2) superior facets

Transverse Ligament Tubercle

  • Small prominence below the medial margin of the superior articular facet
  • Serves as an attachment point for the transverse ligament of the atlas

ANTERIOR ARCH

Atlas arches 360-degree viewer showing anterior arch with facet for dens and posterior arch with vertebral artery groove

Atlas - Anterior and Posterior Arches, Preview from the app. Download 3D OSTEOLOGY for full 3D control—multiple views, x-ray mode, and unlimited zoom.

  • Forms about one-fifth of the atlas' ring
  • Front is convex with a smooth, oval or circular facet for articulation with the dens

Facet for Dens

  • Located on the concave posterior surface of the anterior arch
  • Ensures stability and movement by articulating with the dens of the axis

Anterior Tubercle

  • Central feature of the anterior arch
  • Attachment site for the Longus colli muscles

POSTERIOR ARCH (ARCUS POSTERIOR ATLANTIS)

  • Forms a large portion of the atlas' ring

Posterior Tubercle

  • Small bump at the center of the posterior arch
  • Represents a rudimentary spinous process
  • Serves as a muscle attachment site

Groove for Vertebral Artery (Sulcus Arteriae Vertebralis)

  • Pathway accommodating the vertebral artery
  • Located as it ascends through the transverse process

BIBLIOGRAPHY

1. Henry G, Warren HL. Osteology. In: Anatomy of the Human Body. 20th ed. Philadelphia: Lea & Febiger; 1918. p. 129–97.

⋮⋮ Atlas (C1) Quiz
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