Atlanto Axial articulations

Ox

• Atlanto Axial articulation is a trochoid joint formed between the atlas and the axis

Ligaments

1. Capsular ligament is very loose.
2. The dorsal atlanto-axial is an elastic membranous ligament which extends from the posterior border of dorsal arch of atlas to anterior border of the arch of axis
3. The ventral atlanto-axial ligament is a thin fibrous band extending between the ventral tubercle of atlas and the ventral spine of axis.
4. The odontoid ligament (Ligamentum dentis) is attached to the dorsal face of the odontoid process of the axis behind and to the interior of the ring of atlas in front.

Motion

Rotation of the atlas in front, carrying the head with it.

Horse

• Since the dens is better developed, the dorsal cap between the axis and atlas is wide. Hence the ligaments covering the space are large and better developed.

Dog

• The odontoid ligament is replaced by two alar and one transverse ligament.
• The two alar ligaments arise on either side of the dens, diverge and end on either side of the foramen magnum.
• The transverse ligament is attached to lateral mass of atlas on either side. It stretches across the dorsal surface of the dens and binds it down on the ventral arch of atlas.