ARTICULATIONS OF THE ATLAS AND AXIS. 



127 



Fig. 115. TRANSVERSE SECTION SIMILAR TO 

 THAT REPRESENTED IN FlG. 113, WITH A 

 SMALLER PORTION OF THE OCCIPITAL BONE, 

 THE CRUCIAL LIGAMENTS BEING REMOVED. 



4, alar or odontoid ligament ; 5, accessory 

 atlanto-axial ligament ; 6, 7, capsular liga- 

 ments of the occipito-atlantal and the atlanto- 

 axial articulations ; 9, placed on the head of 

 the odontoid process; 9, 9', superior or median 

 occipito-odontoid ligament. 



The ligamentum suspensorium dentis 

 or middle odontoid ligament consists of 

 fibres which pass directly upwards from 

 the summit of the odontoid process to 

 the margin of the foramen magnum. 



Fig. 115. 



Fig. 11 6. 



Fig. 116. THE LIGAMENTOUS STRUCTURES WHICH SURROUND THE ARTICULATIONS OP 



THE OCCIPUT AND TWO UPPER VERTEBRAE. 



A, the lower part of the skull sawn transversely through the basilar process, with the 

 atlas and axis, viewed from before. 1, the anterior occipito-atlantal ligament; 2, the 

 middle thickened part or accessory occipito-atlantal ligament ; 3, the anterior atlanto- 

 axial ligament. 



B, the lower part of the skull, with three adjacent vertebra, viewed from behind. 1, 

 the posterior occipito-atlantal ligament ; 2, the posterior atlanto-axial ligament. 



C, the occipital bone sawn transversely through the foramen magnum, and a part of the 

 arches of the atlas and axis removed posteriorly, so as to show the thickened prolonga- 

 tion of the posterior common ligament of the bodies of the vertebra with the apparatus 

 ligamentosus. 



