THE CRANIAL NERVES. 



135 



root, while the third carries all the motor fibres, and with them some 

 of the sensory, so that the third branch of the nerve is partly sen- 



FIG. 



Diagram of the Fifth Nerve and its Distribution : 1, sensitive root ; 2, motor root ; 3, Gas- 

 serian ganglion : I, ophthalmic division ; II, superior maxillary division ; III, infe- 

 rior maxillary division; 4, supraorbital nerve, distributed to the skin of the fore- 

 head, inner angle of the eye, and root of the nose ; 5, infraorbital nerve, to the skin 

 of the lower eyelid, side of the nose, and skin and mucous membrane of the upper 

 lip; 6, mental nerve, to the integument of the chin and edge of the lower jaw, and 

 skin and mucous membrane of the lower lip ; , n, external terminations of the nasal 

 branch of the ophthalmic division, to the mucous membrane of the inner part of the 

 eye and the nasal passages, and to the base, tip, and wing of the nose; /, temporal 

 branch of the superior maxillary division, to the skin of the temporal region ; m, 

 malar branch of the superior maxillary division, to the skin of the cheek and neigh- 

 boring parts; fc, buccal branch of the inferior maxillary division, passing along the 

 surface of the buccinator muscle, and distributed to the mucous membrane of the 

 cheek and to the mucous membrane and skin of the lips; /, lingual nerve, to the 

 mucous membrane of the anterior two-thirds of the tongue; at, auriculo-teniporal 

 branch of the inferior maxillary division, to the skin of the anterior part of the 

 external ear and adjacent temporal region ; .<, x, x, muscular branches, to the tem- 

 poral, masseter, and internal and external pterygoid muscles; ,v, muscular branch, 

 to the mylo-hyoid and anterior belly of the diagastric ; /, sensitive branch of com- 

 munication to the facial nerve. 



sory and partly motor. There is a partial decussation of the fibres 

 in the medulla, but many pass direct to the same side. 



What muscles are supplied by the motor root? 



The muscles of mastication. The temporal, masseter. and both 

 pterygoid muscles, as well as the anterior belly of the digastric 



