TRIFACIAL NERVE. 195 



glands. 1 The movements of the eyeball are not affected by 

 division of the fifth. 



Another of the immediate effects of complete division of 

 the fifth is loss of general sensibility in the tongue. This 

 fact was noted by Mayo, in 1S23, 3 and has been confirmed 

 by other physiologists. Most experiments upon the influ- 

 ence of the fifth over the general sensibility and the sense 

 of taste in the tongue have been made by dividing the 

 lingual branch of the inferior maxillary division. When 

 this branch is irritated, there are evidences of intense pain. 

 When it is divided, the general sensibility and the sense of 

 taste are destroyed in the anterior third or half of the tongue. 

 It will be remembered, however, that the chorda tympani 

 joins the lingual branch of the fifth as it passes between the 

 pterygoid muscles, and that section of this branch of the fa- 

 cial abolishes the sense of taste in the anterior third or half 

 of the tongue. 3 If the gustatory properties of the lingual 

 branch of the fifth be derived from the chorda tympani, 

 lesions of the fifth not involving this nerve would be fol- 

 lowed by loss of general sensibility, but the taste would be 

 unaffected. This has been shown to be the fact by experi- 

 ments upon animals and certain cases of paralysis of general 

 sensibility of the tongue without loss of taste in the human 

 subject, reported by Schiff * and by Lussana, 6 which will be 

 discussed more fully in connection with gustation. 



Among the immediate effects of section of the fifth, is an 

 interference with the reflex phenomena of deglutition. In 

 some recent researches on the action of the sensitive nerves 



1 MAGEXDIE, De I 'influence de la cinquieme paire des nerfs sur la nutrition et leg 

 fonctions de VceiL Journal de physiologie, Paris, 1824, tome iv., p. 179. 



2 MAYO, Anatomical and Physiological Commentaries, Number ii., London, 

 1823, p. 10. 



3 See page 155, et seq. 



4 SCHIFF, Lemons sur la physiologic de la digestion, Florence et Turin, 1867, 

 tome i., p. 103, et seq. 



6 LUSSAXA, Recherches experimentales et observations pathologiques sur les nerfs 

 tugout. Archives de physiologic, Paris, 1869, tome ii,, p. 27, et seq. 



