V 



244 ARTICULATION OF THE LOWER JAW. 



forwards, and' are inserted into the spinous processes of each 

 of the cervical vertebrae above the seventh, and also into the 

 atlas and the os occipitis. Attached to the ligamentum nuchse 

 and to the spine, this membrane seems like a partition between 

 the muscles which lie on each side of the back of the neck. 



After inspecting the different ligaments of the spine, it will be obvious- that the 

 yellow ligaments are among the most important of them ; in consequence of 

 their position, their strength) and their elasticity. 



Articulation of the Lower Jaw, (Temporo maxillary.} 



The glenoid cavity of the tempora4 bone with the tubercle 

 before it, and the condyle of the lower jaw, are covered with 

 cartilages. A cartilage is placed between them called inter- 

 articular) which being flexible, is accommodated to the con- 

 vexity of the condyle and hollowness of the glenoid cavity, 

 and also to the figure of the aforesaid tubercle to which it is 

 extended. A synovial capsule, or bag, invests the glenoid 

 cavity and the tubercle, and covers the upper surface of the 

 cartilage. A second capsule of the same kind is attached to 

 the condyle of the lower jaw, and the lower surface of the car- 

 tilage. A few ligamentous fibres extend from the circumfer- 

 ence of the cavity and tubercle of the temporal bone, over both 

 synovial capsules and the cartilage between them, to the lower 

 jaw below the condyle, and appear to be attached to the 

 cartilage. 



These fibres are collected in such numbers, on the external 

 and internal sides of the articulation, that they have been called 

 the external and internal lateral ligaments. 



Another ligament called stylo-maxillary, is mentioned which 

 arises from the styloid process of the temporal bone, and is in- 

 serted into the lower jaw near its angle ; but this seems rattier 

 appropriated to the stylo-glossus muscle than to this articulation. 



In consequence of this structure, the condyle of the lower 

 jaw moves out of the glenoid cavity upon the tubercle, when 

 the mouth is opened widely. 



