Arch of the atlas

Arch of the Atlas is the most superior cervical vertebra of the spine and is located in the neck. It is unique in its structure and function compared to other vertebrae as it does not have a body or a spinous process. Instead, it is ring-like and consists of an anterior and a posterior arch.

Structure

The Arch of the Atlas is made up of two parts: the anterior arch and the posterior arch. The anterior arch forms about one-fifth of the ring, and its anterior surface is rounded and convex. The posterior arch forms the remaining four-fifths. The upper surfaces of both arches are grooved for the vertebral artery and suboccipital nerve.

Function

The primary function of the Arch of the Atlas is to support the skull. It also allows for the nodding and rotation of the head. The atlas articulates with the axis and the occipital bone, allowing for the rotation of the head.

Clinical significance

Injuries to the Arch of the Atlas can result in serious conditions such as atlanto-axial instability, which can lead to neurological deficits or even death. Diagnosis is typically made through radiography.

See also

• Axis (anatomy)
• Cervical vertebrae
• Vertebral column