1246 



HUMAN ANATOMY 



denialis 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 7nental 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. 



Ophthalmic division, V. nerve 

 Maxillary division, V. nerve 



Gasserian ganglion, inf. sunace 



Otic ganglion 



Br. toaurlculo-temp. nerve 

 Int. pterygoid nerve 

 Br. to tensor palati 



Tensor palati, cut ^ H^. 



Palate process of 

 palate bone 



Int. pterygoid 



Hamulus of int. 

 pterygoid plate 



V. nerve, sensory root 

 V. nerve, motor root 



Mandibular division, V. nerve 



pani, cut (tensor tympant 

 Br. from otic ganglion to 

 Cartilaginous portion (»l 

 Eustach. tube, cut 



Petrosa of temporal 

 bone 



Small superf. 

 petrosal nerve 

 Br. from ganglion to 

 chorda tympani 



Middle meningeal 

 artery and plexus 

 Carotid canal outer, 

 Auriculo-tem- [wall 

 poral nerve 

 Lingual nerve 



Inf. dental nerve 



Int. maxillary artery 



^- / I 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 measures 

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

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

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

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

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

 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. petrosus superficialis minor). The latter estab- 

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

 pharyngeal nerve by way of its tympanic branch (page 1075) on the one hand and, 

 by means of communicating filaments, between the otic and the geniculate ganglion 

 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 and 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 

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



