DISSECTION OF THE HEAD AND NECK. 189 



3. The Nerve to the Masseter and Temporal Muscles. This is given off 

 from the front of the trunk. It detaches branches to the temporal 

 muscle, and is then continued through the corono-condyloid notch to 

 end in the masseter. 



4. The Buccal Nerve is a larger branch than any of the foregoing. 

 It arises at the same point as the preceding nerve, and passing through 

 the external pterygoid muscle, to which and the temporal muscle it 

 supplies branches, it is continued as a sensory nerve to the cheek. 



The Inferior Dental Nerve is the larger of the two branches into 

 which the trunk of the inferior maxillary nerve divides. Under cover of 

 the external pterygoid muscle, it crosses over the internal maxillary artery, 

 in company with the lingual nerve, which lies in front of it. It then 

 passes in between the two pterygoid muscles, where it places itself in 

 front of the inferior dental vessels. It has already been seen issuing 

 from between the muscles to gain the inferior dental canal by passing' 

 between the inner muscle and the bone. 



The Mylo-hyoid Nerve is detached from the posterior edge of the foi-e- 

 going nerve at its point of formation. It crosses the inferior dental 

 vessels between the two pterygoid muscles, and then descends between 

 the inner muscle and the bone. It has already been traced to the 

 digastric (lower belly) and mylo-hyoid muscles. 



The Lingual or Gtjstatoet Nerve is only slightly smaller than the 

 inferior dental. It lies immediately in front of that nerve as far as the 

 posterior edge of the external pterygoid muscle, where it passes forwards 

 between the internal pterygoid and the bone to reach the tongue. It is 

 a sensory branch ; and, while between the two muscles, it is joined by 

 the chorda tympani. 



The Chorda Tympani Nerve. This is a branch detached from the 

 7th nerve in the aqueduct of Fallopius. It passes across the 

 tympanum, or middle ear, and issues from the petrous temporal bone 

 by the styloid foramen. It then descends on the guttural pouch ; and 

 crossing beneath the internal maxillary artery and the trunk of the 

 inferior dental nerve, it joins the lingual nerve between the two 

 pterygoid muscles. 



The Otic Ganglion. This ganglion is at best minute, and sometimes 

 absent, or at least not well defined. To examine it well, it is neces- 

 sary to make a special preparation, exposing the inner aspect of the 

 inferior maxillary nerve at its point of emergence from the cranium. 

 The ganglion is placed on the inner side of the before-mentioned nerve- 

 trunk near the origin of its buccal branch. Its afferent branches are : 

 (1) twigs from the buccal branch of the inferior maxillary nerve ; (2) the 

 small superficial petrosal nerve from the 7th ; (3) twigs from the sympa- 

 thetic branches that accompany the internal maxillary artery. It 

 supplies efferent branches to: (1) the tensor palati muscle; (2) 



