OCCIPITO-SPINAL LIGAMENTS. 



137 



Another bursa lies between the odontoid and the anterior arch of the atlas. The 

 transverse ligament and the two check ligaments are in series with the interarticular 

 ligaments of the heads of the ribs. 



The other ligaments of this region are in the main simple membranes connect- 



FiG. 167. 



Upper end of occipito-axial ligament 



Lateral odontoid ligament 



Occipito-atlantal joint 



Cruciform ligament 



Atlas 



Atlanto-axial joint 



Axis 



Occipito-axial ligament, fused with dura, 

 turned down 



Dua 



Fig. 168. 



Front of 

 foramen 

 magnun 



Middle 



odontoid 



ligament 



Lateral odontoid 

 igament 



Bursa on back of 

 odontoid 



Back of occiput and arches removed ; occipito-axial ligament cut and turned down. 



ing neighboring parts. The anterior occipito-atlantal ligament ' ( Fig. 165 ) 

 extends between the front of the foramen magnum and the anterior arch of the 

 atlas ; the anterior atlanto-axial (Fig. 165) is in serial continuation with it. A 

 distinct rounded, raised band, the accessory occipito-atlantal, passes in the 

 median line from the under side of the 

 occiput to the front tubercle of the atlas 

 (Fig. 165), and thence to the body of the 

 axis, where it joins the anterior common 

 ligament of the spine. 



The occipito-axial ligament^ {^appa- 

 ratus liganientosus) (Fig. 167) descends in- 

 side the spinal canal from the basilar process 

 to the body of the axis, where it joins the 

 posterior common ligament and completely 

 conceals the odontoid process and its special 

 ligaments. 



The posterior occipito-atlantal' and 

 the posterior atlanto-axial ligaments* 

 lie in the region of the arches (Fig. 166). The 

 former extends between the posterior border 

 of the foramen magnum and the arch of the 

 atlas ; the latter between the arch of the 



atlas and that of the axis. These are in series with the ligamenta subflava, but differ 

 from them in being non-elastic. In the former of these membranes there is an 

 opening just behind the facets on the atlas for the condyles, bridged over by a band, 

 for the entrance of the vertebral artery. 



^^ Atlas 



Transverse liga- 

 ment, cut 



Articular facet of 

 axis 



Posterior surface of odontoid process shown by 

 removal of middle of transverse ligament ; basilar 

 process is thrown strongly upward. 



' Memlirana atlantooccipitalis anterior 

 atlantoepistrophica. 



 Membrana tectoria. •* Membrana atlantooccipitalis posterior. * Membrana 



