462 NERVOUS SYSTEM. 



It then radiates into filaments, which supply the tonsil gland 

 and the muscular and membranous structure of the soft palate. 

 The other smaller palatine also traverses, after the same man- 

 ner, its own canal, and is likewise distributed to the tonsil gland 

 and to the soft palate. 



Third Branch of the Trigeminus. 



The Third Branch of the*Trigeminus (Nervus Inframaxil- 

 laris) is the largest of the three. It arises from the posterior 

 inferior part' of the ganglion of Gasser, and having anastomosed 

 with the cavernous ganglion of the sympathetic nerve by fila- 

 ments, which are not constant, it emerges from the cranium 

 through the foramen ovale of the sphenoid bone. A portion 

 of this branch, as mentioned, does not enter into the composi- 

 tion of the ganglion of Gasser, but proceeds immediately from 

 the pons varolii. 



The inferior maxillary nerve, at its exit from the foramen 

 ovale, is covered by the pterygoideus externus muscle, and 

 commonly divides there into two branches, one anterior and the 

 other posterior or else sends off two sets of branches the first 

 for the muscles of mastication and the second set for the low- 

 er jaw and tongue. 



The Anterior Branch, or set, which is much smaller than the 

 other, radiates into five fasciculi; the masseter nerve; the two 

 temporal; the buccal; and the pterygoid. 



a. The Masseter Nerve is directed horizontally outwards 

 and backwards, along the external margin of the pterygoideus 

 externus, and in front of the temporo-maxillary articulation: 

 it leaves some filaments with the latter, and then passing be- 

 tween the insertion of the temporal and of the external ptery- 

 goid muscle, over the concave edge of the bone, between the 

 condyle and the coronoid process of the lower jaw, it penetrates 

 into the substance of the masseter muscle, and is distributed 

 through it. 



b. The two Temporal branches arise by a common fascicu- 

 lus, but sometimes differently. They pass outwards, horizon- 

 tally, between the external pterygoid muscle and zygomatic 

 fossa. They then ascend on the side of the temporal bone, be- 



