606 THE CRANIAL NERVES. 



muscle, and is directed nearly horizontally outwards through the sigmoid 

 notch of the lower jaw to the posterior border of the masseteric muscle, 

 which it enters on the deep surface. It gives a filament or two to the 

 articulation of the jaw, and occasionally furnishes a branch to the tem- 

 poral muscle. 



The buccal branch pierces the substance of the external pterygoid muscle, 

 and courses downwards and forwards to the face, in close contact with the 

 deep surface of the temporal muscle at its insertion. It furnishes a branch 

 to the external pterygoid muscle as it pierces it, and on emerging gives 

 two or three ascending branches to the temporal muscle. It divides into 

 two principal branches, an upper and a lower, which communicate with the 

 facial nerve in a plexus round the facial vein, and are distributed to the 

 integument, the buccinator muscle, and the mucous membrane. 



The external pterygoid branch, is most frequently derived from the buccal 

 nerve. It is sometimes a separate offset from the smaller portion of the 

 lower maxillary nerve. 



The nerve of the internal pterygoid muscle is closely connected at its 

 origin with the otic ganglion, and enters the inner or deep surface of the 

 muscle. 



AURICFLO-TEMPORAL NERVE. 



The auriculo-temporal nerve takes its origin close to the foramen ovale. It 

 often commences by two roots, Between which may be placed the middle 

 meningeal artery. It is directed at first backwards, beneath the external 

 pterygoid muscle, to the inner side of the articulation of the jaw ; then 

 changing its course, it turns upwards betwt ea the ear and the joint, covered 

 by the parotid gland ; and emerging from this place, it finally divides iuto 

 two temporal branches which ascend towards the top of the head. 



(a) Communicating branches. There are commonly two branches which pass 

 forward round the external carotid artery, and join the facial nerve. Filaments to 

 the otic ganglion arise near the beginning of the nerve. 



(b) Parotid branches are given from the nerve while it is covered by the gland. 



(c) Auricular branches. These are two in number. The lower of the two, arising 

 behind the articulation of the jaw, distributes branches to the ear below the external 

 meatus; and sends other filaments round the internal maxillary artery to join the 

 sympathetic nerve ; the upper branch, leaving the nerve in front of the ear, is dis- 

 tributed in the integument covering the tragus and the pinna above the external 

 auditory meatus. Both are confined to the outer surface of the ear. 



(d) Branches to the meatus auditorius. These, two in number, spring from the 

 point of connection of the facial and auriculo-temporal nerves, and enter the interior 

 of the auditory meatus between the osseous and cartilaginous parts. One of them 

 sends a branch to the membrana tympani. 



(e) Articular branch. The nerve to the temporo-maxillary articulation comes 

 from one of the preceding branches, or directly from the auriculo-temporal nerve. 



(/) Temporal branches. One of these, the smaller and posterior of the two, 

 distributes filaments to the anterior muscle of the auricle, the upper part of the 

 pinna and the integument above it. The anterior temporal branch extends with 

 the superficial temporal artery to the top of the head, and ends in the integument. 

 It is often united with the temporal branch of the upper maxillary nerve. Meckel 

 mentions a communication between this branch and the occipital nerve. 



GUSTATORY NERVE. 



The gustatory nerve, or lingual branch of the fifth, descends under 

 cover of the external pterygoid muscle, lying to the inner side and in 



