What is the articulation of the atlas with the epistropheus or axis?

What it is

• The articulation of the atlas with the axis is of a complicated nature, comprising no fewer than four distinct joints. There is a pivot articulation between the odontoid process of the axis and the ring formed by the anterior arch and the tranverse ligament of the atlas (see Fig.
• 306) ; here there are two joints: one between the posterior surface of the anterior arch of the atlas and the front of the odontoid process; the other between the anterior surface of the ligament and the back of the process. Between the articular processes of the two bones there is on either side an arthrodial or gliding joint. The ligaments connecting these bones are: Two Articular Capsules. The Posterior Atlantoaxial. The Anterior Atlantoaxial. The Transverse.
• The Articular Capsules ( capsulæ articulares; capsular ligaments ). —The articular capsules are thin and loose, and connect the margins of the lateral masses of the atlas with those of the posterior articular surfaces of the axis. Each is strengthened at its posterior and medial part by an accessory ligament, which is attached below to the body of the axis near the base of the odontoid process, and above to the lateral mass of the atlas near the transverse ligament.