XI. Additional Vertebral Column Arthrology: Atlanto-Occipital Joint Flashcards
What is the classification of the atlant” o-occipital joint?
synovial (diarthrosis) ellipsoidal
What are the attachment sites of the anterior atlanto-occipital lig?
it is attached to the upper margin of the anterior arch of C1 and to the anterior margin of the foramen magnum
What is the median thickening of the anterior atlanto-occipital lig. called?
the anterior longitudinal lig.
What is the classic function of the anterior atlanto-occipital lig?
it brakes or limits “extension” of the skull over the cervical spine
Based on the amount of ossification of the anterior free margin of the posterior atlanto-occipital lig. what structures will form?
an imcomplete ponticulus posticus or a complete ponticulus posticus
What names are given to the opening formed by the ponticulus posticus?
arcuate foramen or retroarticular canal
What is the classic function of the posterior atlanto-occipital lig?
it brakes or limits axial rotation, flexion, and perhaps lateral bending of the skull on atlas
What amounts of flexion - extension is accomodated by the atlanto-occipital joint?
about three to eight degrees one side axial rotation
What amount of lateral bending is accommodated by the atlanto-occipital joint?
about five degrees
Which motion is best accomodated by the atlanto-occipital joint?
flexion - extension
