1246 



HUMAN ANATOMY. 



dentalis inferior) which supplies filaments to the molar and premolar teeth, one filament to each 

 fang, and the adjacent portion of the gum. 



c . The incisor branch (n. alveolaris inferior anterior) is the smaller of the terminal divisions 

 and continues forward within the mandible the course of the inferior dental nerve from the 

 mental foramen to the mid-line. It supplies the canine and incisor teeth. 



d. The mental nerve (n. mentalis) (Fig. 1063) is much the larger terminal 

 branch of the inferior dental. Emerging from the mental foramen, it breaks up under 

 cover of the depressor anguli oris muscle into a number of filaments which supply the 

 skin of the chin and the integument and mucous membrane of the lower lip. It forms 

 a free communication with the supramandibular branch of the facial nerve. 



The Otic Ganglion. The otic or Arnold' s ganglion (g. oticum) (Fig. 1064) is 

 one of the two ganglia associated with the mandibular nerve. It is a small flattened 



FIG. 1064. 



j Ophthalmic division.V. nerve 



.vUxillary division, V. nerve 



Gasserian ganglion, inf. surface 



V. nerve, sensory root 

 V. nerve, motor root 



Mandibular division, V. nerve 



Tensor tym pani, cut (tensor tympanl 

 Br. from otic gangliun to 

 Cartilaginous portion of 

 l-.iistai.li. tube, cut 



Petrosa of temporal 



bone 



Small superf. 



petrosal nerve 



Br. from ganglion to 



chorda tym pani 



Middle meningeal 

 artery and plexus 

 Carotid canal outer, 

 Auriculo-tem- [wall 

 poral nerve 

 Lingual nerve 



Inf. dental nerve 



Otic ganglion 



Br. to aurlculo-temp. nerve 



Int. pterygoid nenre 



Br. to tensor palati- -M 



Tensor palati. cut- 



Palate proces 

 palate b< 



Int. pterygoid-^ 



Hamulus of int 

 pterygoid plate 



Int. maxillary artery 

 Temporal artery 



Ext. carotid artery 

 Styloid process 



Otic ganglion and branches seen from mesial aspect, section of skull being not sagittal, but approaching 



plane of long axis of petrosa. 



body, of irregularly oval or stellate outline and reddish-gray color, and measun 

 about 4 mm. in its longest or antero-posterior dimension. It lies just below th 

 foramen ovale on the mesial side of the mandibular nerve and covers or even encl 

 the origin of the internal pterygoid nerve. Internally the ganglion is in relation wi 

 the tensor palati muscle and the cartilaginous portion of the Eustachian tube an 

 posteriorly with the middle meningeal artery. It is a sympathetic ganglion and co 

 tains numerous stellate neurones which are characteristic of such structures. 



Roots. Of the communications that the otic ganglion receives from several 

 sources, some are regarded as its roots, of which the sensory root is contributed by 

 small superficial petrosal nerve < n. pctrosus superficialis minor). The latter estab- 



lishes connection between the otic ganglion and the petrous ganglion of the glosso- 



Cluryngeal nerve l>v way of its tympanic branch (page 1075) on the one * 



y means of communicating filaments, between the otic and the geniculate 



,o- 



a, 



on 



of the- facial nerve on the other. As the continuation of the tympanic nerve, after 

 union with the filaments from the geniculate ganglion, the small superficial petrosal 

 leaves the upper ami fore part of the tympanic cavity, traverses a small canal in the 

 temporal bone, and emerges on the upper surface of the latter, to the outer side of 

 the hiatus Fallopii. It then turns downward, passes through the petro-sphenoidal 

 figure or through a special canal in the sphenoid bone, and joins the otic ganglion. 



