

806 THE NERVOUS SYSTEM. 



reflected upward at the pterygoid ridge of the sphenoid to the front of the tem- 

 poral fossa. It is often given off from the buccal branch after the latter has 

 pierced the external pterygoid muscle. The third branch (middle deep temporal) 

 passes outward over the External pterygoid muscle and enters the deep surface 

 of the Temporal muscle. 



The buccal branch passes forward between the two heads of the External 

 pterygoid, and downward beneath the inner surface of the coronoid process of the 

 lower jaw, or through the fibres of the Temporal muscle, to reach the surface of 

 the Buccinator, upon which it divides into a superior and an inferior branch. It 

 gives the branch to the External pterygoid during its passage through that 

 muscle, and is usually joined with the anterior branch of the deep temporal nerve. 

 The upper branch supplies the integument and upper part of the Buccinator 

 muscle, joining with the facial nerve round the facial vein. The lower branch 

 ,,/passes forward to the angle of the mouth : it supplies the integument and'Bucci- 

 ' nator muscle, as well as the mucous membrane lining the inner surface of that 

 muscle, and joins the facial nerve. 1 



The External Pterygoid Nerve is most frequently derived from the buccal, but 

 it may be given off separately from the anterior trunk of the nerve. It enters the 

 muscle on its inner surface. 



The posterior and larger division of the inferior maxillary nerve is for the 

 most part sensory, but receives a few filaments from the motor root. It divides 

 into three branches : auriculo-temporal, lingual (gustatory), and inferior dental. 



The Auriculo-temporal Nerve generally arises by two roots, beneath which the 

 middle meningeal artery passes. It runs backward beneath the External ptery- 

 goid muscle to the inner side of the neck of the lower jaw. It then turns upward 

 with the temporal artery, between the external ear and condyle of the jaw, under 

 cover of the parotid gland, and, escaping from beneath this structure, ascends 

 over the zygoma and divides into two temporal branches. 



The branches of communication are with the facial and with the otic ganglion. 

 The branches of communication with the facial, usually two in number, pass 

 forward from behind the neck of the condyle of the jaw, to join the temporo-facial 

 division of this nerve .at^the posterior border of the Masseter muscle. They form 

 one of the principal branches" of coTnmuni cation between the facial and the fifth 

 nerve. The filaments of communication with the otic ganglion are derived from 

 the commencement of the auriculo-temporal nerve. 



The branches of distribution are 



Auricular, inferior and superior. Articular. 



Branches to the meatus auditorius. Parotid. 



Temporal, anterior and posterior. 



The inferior auricular arises behind the articulation of the jaw, and is distrib- 

 uted to the ear below the external meatus : other filaments twine round the 

 internal maxillary artery and communicate with the sympathetic. The superior 

 auricular arises in front of the external ear, and supplies the integument cover- 

 ing the tragus and pinna. 



Branches to the meatus auditorius, upper and lower, arise from the point 

 of communication between the auriculo-temporal and facial nerves, and are 

 distributed to the meatus. A filament from the upper passes to the membrana 

 tympani. 



A branch to the temporo-maxillary articulation is usually derived from the 

 auriculo-temporal nerve. 



The parotid branches supply the parotid gland. 



The anterior temporal accompanies the temporal artery to the vertex of the 

 skull, and supplies the integument of the temporal region, communicating with 

 the facial nerve and the temporal branch of the temporo-malar from the superior 



1 There seems to be no reason to doubt that the branch supplying the Buccinator muscle is entire- 

 ly a nerve of ordinary sensation, and that the true motor-supply of this muscle is from the facial. 



