Craniovertebral joints and ligaments

(A) Ligaments of the atlanto-occipital and atlantoaxial joints. The tectorial membrane and the right side of the cruciate ligament of the atlas have been removed to show the attachment of the right alar ligament to the dens of vertebra C2 (axis).
(B) The hemisected craniovertebral region shows the median joints and membranous continuities of the ligamenta flava and longitudinal ligaments in the craniovertebral region.