224 



THE CRANIAL NERVES. 



sphenoid ; the facial and auditory nerves enter the internal auditory meatus of the 

 petrous bone ; the glosso-pharyngeal, pneumo-gastric, and spinal accessory nerves 

 descend through the middle compartment of the jugular foramen between tho 

 petrous and occipital bones ; and the hypoglossal nerve passes through the anterior 

 condylar foramen of the occipital bone. 



Fig. 142. A. SEMIDIAGRAMMATIC VIEW OP A DEEP DISSECTION OF THE CRANIAL NERVES ON THK 



LEFT SIDE OF THE HEAD. B. EXPLANATORY OUTLINE OF THE SAME. (Allen Thomson.) 



The Roman numerals from I to XII indicate the roots of the several cranial nerves as they lie in or 

 near their foramina of exit ; V, is upon the large root of the fifth with the Gasserian ganglion in front ; 

 C I, the suboccipital or first cervical nerve ; C VIII, the eighth. The branches of the nerves are 

 marked as follows, viz. : 1, supraorbital branch of the fifth ; 2, lachrymal passing into the gland ; 

 3, nasal passing towards the anterior internal orbital canal, and giving the long root to the ciliary 

 ganglion, 4' ; 3', termination of the nasal nerve ; 4, lower branch of the third nerve ; 5, superior 

 maxillary division of the fifth passing into the infraorbital canal ; 5', the same issuing at the infra- 

 orbital foramen and being distributed as inferior palpebral, lateral nasal, and superior labial nerves, 

 5"; 6, ganglion of Meckel and Vidian nerve passing back from it; 6', palatine and other nerves 

 descending from it ; 6", large superficial petrosal nerve ; 7, posterior dental nerves ; 7', placed in the 

 antrum, which has been opened, points to the anterior dental nerve ; 8, inferior maxillary division of 

 the fifth immediately below the foramen ovale ; 8', some of the muscular branches coming from it ; 

 8 x , the auriculo-temporal branch cut short, and above it the small superficial petrosal nerve connected 

 with the facial; 9, buccal and external pterygoid; 10, lingual nerve ; 10', its distribution to the side 

 and front of the tongue and to the sublingual gland : 10", submaxillary ganglion ; below 10, the chorda 

 tympani passing forwards from the facial above 12, to join the lingual nerve ; 11, inferior dental 

 nerve; 11', the same nerve and part of its dental distribution exposed by removal of the jaw ; 11", its 

 termination as the mental nerve ; 11"', its mylo-hyoid branch ; 12, twigs of the facial nerve imme- 

 diately after its exit from the stylo-mastoid foramen to the posterior belly of the digastric and to the 

 stvlo-hyoid muscle ; 12', temporo-facial division of the facial ; 12", cervico- facial division ; 13, trunk 



