Atlas Anatomy (C1) Overview

Atlas (C1)

• Features superior articulating processes with facets that form the synovial condylar joint with occipital condyles of the occipital bone.
• Anterior and posterior tubercles identify the front and back sides of the cervical vertebra.
• Transverse processes are present, with transverse foramina allowing passage for vertebral arteries.
• The vertebral foramen is a large opening where the spinal cord runs through.
• Articulating surface for the dens (odontoid process) of C2 allows for rotation around this pivot point.
• Inferior articulating processes with facets articulate with superior articulating processes of C2, forming a synovial pivot joint.

Axis (C2)

• The dens (odontoid process) protrudes superiorly, providing a pivot point.
• Superior articulating processes articulate with the inferior articulating processes of C1.
• Vertebral foramen allows spinal cord passage, while the spinous process protects the spinal cord.
• The body or centrum serves as the weight-bearing structure in the cervical vertebra.
• Transverse processes and foramina are visible, confirming the route for vertebral arteries.
• Inferior articulating processes align with superior processes of lower cervical vertebrae.

Articulation Between Atlas and Axis

• The odontoid process serves as the pivot point for rotational movement between C1 and C2.
• The interaction at the anterior arch and tubercle facilitates this pivotal motion.
• This articulation allows for side-to-side movement, emphasizing the function of the synovial pivot joint.

Atlas (C1)

• Features superior articulating processes with facets that form a synovial condylar joint with occipital condyles of the occipital bone, allowing head movement.
• Anterior and posterior tubercles define the front and back sides of the cervical vertebra for orientation.
• Transverse processes contain transverse foramina, which permit the passage of vertebral arteries, critical for blood supply to the brain.
• The vertebral foramen is large, facilitating the safe passage of the spinal cord.
• Includes an articulating surface for the dens (odontoid process) of C2, enabling rotational movement.
• Inferior articulating processes connect with superior articulating processes of C2 to form a synovial pivot joint allowing neck rotation.

Axis (C2)

• The dens (odontoid process) projects superiorly, serving as a critical pivot point for rotation.
• Superior articulating processes engage with inferior articulating processes of C1, securing the connection between the two vertebrae.
• The vertebral foramen enables the passage of the spinal cord, while a spinous process protects it from external impacts.
• The body (centrum) acts as the primary weight-bearing structure among cervical vertebrae, sustaining necessary loads.
• Transverse processes with foramina confirm the pathway for vertebral arteries, maintaining cerebral circulation.
• Inferior articulating processes align with superior processes of lower cervical vertebrae, allowing for enhanced flexibility in movement.

Articulation Between Atlas and Axis

• The odontoid process functions as the central pivot point for rotational movement between C1 and C2.
• Interaction at the anterior arch and tubercle of C1 enhances this pivotal motion, enabling greater neck mobility.
• This articulation primarily facilitates side-to-side head movement, highlighting the effectiveness of the synovial pivot joint in cervical motion.

Explore the anatomy of the Atlas (C1), the first cervical vertebra. This quiz covers its unique features, including the articulating processes, transverse foramina, and the vertebral foramen. Understand the role of the Atlas in forming the synovial condylar joint with the occipital bone.