ARTICULATIONS. LIGAMENTS. 



467 



\\'lia/ is peculiar about tlic avis .' 



The odontoid process, the dissociated body of the atlas, is fused to the uxiv 

 \'anic the fi^ttnienfs tluit Iniiti the axis to tlic atlas. 

 These ligaments have to do with two distinct classifications : 



f Class. Diarthrosis. 



I Subdivision. .\rthn n lia. 



I < y^.v.v. 1 )iarthrosis. 



I Subdivision, Trochoides. 

 Tlie ligaments are of periosteal derivation, called: (i) Anterior atlanto 

 axoidean ; (2) posterior atlanto-axoidean ; (3) two capsular ligaments lined by 



I. The lateral atlanto-axoidean 



2. The central atlanto-axoidean 



Left lateral 

 odontoid 

 ligament 



Transverse ligament 



Inner part of capsular ligament 

 of oooipito-atlantal joint 



Posterior oooipito-atlantal 

 ligament 



Descending portion of crucial 

 ligament 



Posterior atlanto-axoidean 

 ligament 



InterspinouB ligament 



Ugamentum subflavum 



Central odontoid 



ligament 



Anterior oooipito- 

 atlantal ligament 



Atlan to-odontoid 

 ynovial ue 



Anterior atlanto- 

 axoidean ligament 



FIG. 341. VERTICAL ANTERO- POSTERIOR SECTION OF SI-INAL COLUMN THROUGH MEDIAN 



LINE, SHOWING LlGAMRNTS. 



synovial membrane ; (4) the transverse ligament extending between the tuber- 

 cles of the lateral masses ; (5) the atlanto-odontoid capsular ligament. 



THE ATLANTO-OCCIPITAL ARTICULATION AND LIGAMENTS. 



1. Class. Diarthrosis, because of free movement and synovia. 



2. Subdivision. Double condylarthrosis. 



3. Technical Xante. Occipito-atlantal, or atlanto-occipital. 



4. Ostcological Units. Occipital bone and atlas. 



5. Subdivisions. Condyles of occipital bone and lateral masses of atlas. 



