THE BRAIN. 



517 



not an uncommon thing to hear patients complain of headaches 

 which seem to them to be in the brain itself. These deep-seated 

 headaches may be due to affections of one or more of the recurrent 

 branches which come off from the divisions of the nerve, and 

 which are distributed to the dura mater and bones of the skull. 

 Lingual (Gustatory) Nerve. This nerve is sometimes called 

 the " lingual branch of the fifth nerve." It is the branch which 

 is distributed to the mucous membrane of the mouth and the gums, 

 and to the mucous membrane and papillae of the tongue. It sup- 

 plies the tongue with tactile sensibility, a quality of great advan- 

 tage in enabling one to detect the physical properties of food, to 



FIGS. 305, 306. Distribution of the cutaneous sensitive nerves upon the head : 

 owa, orni, the occiput, ma j. and minor (from the N. cervical II. and III.) ; am, N. 

 auricular magn. (from X. cervic. III.) ; cs, N. cervical superfic. (from N. cervic. III.) ; 

 Fi, first branch of the fifth (so, N. supraorbit. ; st. N. supratrochl. ; it, N. infra- 

 trochl. ; e, N. ethmoid. ; I, N. lacrimal.) ; Vi, second branch of the fifth (sm, N. 

 subcutan. malfe sen zygomaticus) ; Fs, third branch of fifth (at, N. auriculotempor. ; 

 b, N. buccinator ; m, N. mental.) ; B, posterior branches of the cervical nerve. 



recognize in it the presence of hard objects which it would be 

 injurious to swallow, and to determine when it is ready for 

 deglutition. Besides this tactile sensibility the lingual nerve, 

 according to some authorities, suppli'es the anterior two-thirds of 

 the tongue with the sense of taste, a special sense, and this power 

 is lost when the fifth pair or the lingual branch is divided. For 

 a further consideration of this nerve see p. 535. 



Mastication. The muscles that have been mentioned as receiv- 

 ing branches of the inferior maxillary division are those concerned 

 in the act of mastication. In this act the temporal and masseter 

 close the mouth, the mylohyoid and digastric open it, while the 

 pterygoids produce the lateral movement of the lower jaw. 

 Division of the inferior maxillary division paralyzes, therefore, all 



