ARTICULATION OF THE LOWER JAW. 263 



cushions in the joints in consequence of their increased vascu- 

 larity. M. Beclard teaches, that it is neither a follicular nor a 

 glandular secretion, nor a transudation, but a perspiration, in 

 which a perfect equilibrium is kept up between its exhalation 

 and its absorption. Its use is to diminish friction, and, conse- 

 quently, to facilitate the sliding of the bones upon each other. 



CHAPTER IV. 



ARTICULATION OF THE LOWER JAW. 



THE articular connexion, here, is formed by that portion of the 

 glenoid cavity anterior to the fissure, and by the condyle of the 

 lower jaw. Each surface is covered by thin cartilage; and a 

 thin, loose, irregular, fibrous, capsular ligament, arises from the 

 articular margin of one bone, to be inserted into that of the other. 

 Besides this, there are four other ligaments for strengthening 

 the joint, an inter-articular cartilage, and two synovial mem- 

 branes. 



The External Ligament (Membrana Articularis Ligamen- 

 tosa) arises from the inferior margin of the root of the jugal or 

 zygomatic process of the temporal bone, and from the anterior 

 side of the meatus externus, and is inserted into the neck of the 

 condyloid process. It is somewhat triangular, having the base 

 upwards. Just in advance of this, and separated from it by a 

 small fissure, is another triangular ligament, the discovery of 

 which is claimed by Caldani.* It arises from the anterior part 

 of the inferior margin of the zygomatic process of the tempo- 

 ral bone, and is inserted into the neck of the bone in advance 

 of the other. 



The Internal Ligament (Lig. Maxillce Laterals) arises from 

 the extremity of the spinous process of the sphenoid bone, and 

 from the posterior margin of the glenoid cavity, that is the pro- 

 cessus vaginalis,and going downwards and outwards, is inserted 



* Tabul. Anat. Venetiis, 1802. 



