A R TICUL A 77 6LA 'S. L I GA ME NTS. 



467 



\Vliat is peculiar about the axis / 



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

 Xatne the ligaments that bind the axis to the atlas. 

 These ligaments have to do with two distinct classifications : 



-ri i , i ,, . , f Class. Diarthrosis. 



1. 1 he lateral atlanto-axoidean ,,..... ,. 



(_ Subdivision. Arthrodia. 



^, . , f Class. Diarthrosis. 



2. 1 he central atlanto-axoidean ...... 



( Subdivision. 1 rochoides. 



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

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



Left lateral 

 odontoid 

 ligament 



Transverse ligament 



Inner part of capsular ligament 

 of occipito-atlantal j oint 



Posterior oeeipito-atlantal 

 ligament 



Descending portion of crucial 

 ligament 



Posterior atlanto-axoidean 

 ligament 



Interspinous ligament 



Ligamentum subflavum 



Central odontoid 



ligament 



Anterior occipito- 

 atlantal ligament 



Atlanto-odontoid 

 synovial sac 



Anterior atlanto- 

 axoidean ligament 



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



LINE, SHOWING LIGAMENTS. 



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 Name. Occipito-atlantal, or atlanto-occipital. 



4. Osteological Units. Occipital bone and atlas. 



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



