JOINTS OF THE NECK 



363 



in some cases a communication exists between the two synovial 

 cavities. 



The vertical part of the cruciate ligament consists of an 

 upper and a lower limb, which are termed the crura. Both 

 are attached to the dorsal surface of the transverse ligament. 

 The crus superius is the longer and flatter of the two, and 

 extends upwards on the posterior aspect of the dens to be 

 attached to the upper aspect of the basilar part of the 

 occipital bone immediately beyond the anterior margin of 



Membrana tectoria 

 Crus superius 



Lateral 



mass of 



atlas 



Atla 

 pistropheal joint 



Body of Epistro- 

 pheus 



Apical 

 ligament 



Alar 

 *TJ" ligament 



I] Crus 

 superius 

 Transvei 

 ligament 



Accessory atlanl 



epistropheal 



ligament 



Crus inferius 



Membrana tectoria 



FIG. 145. Dissection showing the posterior aspects of the Ligaments con- 

 necting the Occipital Bone, the Atlas, and the Epistropheus with each 

 other. 



the foramen magnum. The crus inferius, much shorter, 

 extends downwards, and is fixed to the posterior aspect of 

 the body of the epistropheus. 



Dissection. Detach the superior crus from the occipital bone, and 

 throw it downwards. The apical ligament is thus displayed, and a better 

 view of the alar ligaments is obtained. 



Ligamentum Apicis Dentis. The apical ligament of the 

 dens consists of two parts an anterior and a posterior. The 

 posterior part is a rounded cord-like ligament which is attached 

 below to the summit of the dens, and above to the anterior 

 margin of the foramen magnum. This ligament, inasmuch 



