ALL    –           C1 to sacrum

                        Attached to vertebral bodies

                        Gets wider as move caudal


PLL     –           C2 to sacrum

                        Attached to discs

                        Gets narrower as move caudal


Tectorial membrane     –           continuation of PLL

                                                C2 to foramen magnum

                                                Behind cruciate ligament / alar / apical ligaments


Anterior / posterior atlanto-occipital membranes

                        From arch C1 to foramen magnum

                        Posterior deficient to allow C1 nerve and vertebral artery through


Cruciate ligament        –           transverse – attached across atlas

                                                Longitudinal – from body C2 to foramen magnum


Apical ligament           –           weak

                                                Tip of dens to foramen magnum

                                                Remnant of notochord


Alar ligaments             –           strong

                                                Oblique to apical

                                                Attached to foramen magnum