498 



MUSCULAR MOTION. 



Fig. 204. 



it was termed by Bellinger! 1 nervus masticatorius ; and by Sir Charles 

 Bell, long afterwards, motor or manducatory portion of the fifth nerve. 

 To this smaller fasciculus of the fifth, twigs from the ganglionic portion 

 of the nerve are distributed. The ganglionless portion, and portio dura 

 of the seventh, Mr. Mayo conceives to be voluntary nerves to parts, 

 which receive sentient nerves from the larger or ganglionic portion of 

 the fifth. The facial nerve, however, after it has passed through the 

 parotid gland, becomes sensory also, owing to its having received a 

 twig from the fifth pair. 



Pathology affords numerous examples of injury done to the facial 

 nerve. In some of these, the nerve itself may be in a morbid condi- 

 tion in a portion of its 

 course ; in others, the part 

 of the encephalon, whence 

 the nerve originates, may 

 be the seat of the lesion. 

 The prognosis will, of 

 course, vary according to 

 the seat; but, as a general 

 rule, paralysis of the facial 

 nerve is not of great mo- 

 ment. The author has seen 

 several cases of partial 

 paralysis of this kind; 

 some of which have wholly 

 disappeared; but in others 

 the loss of power appears 

 to be permanent. In a 

 case, which presented itself 

 to him in the Baltimore 

 Infirmary, the mischief was 

 probably seated near the 

 origin of the nerve, as it 

 resulted from serious injury 

 to the head. A carriage- 

 horse, belonging to a friend, 

 by exerting considerable 

 power, forced its head through an aperture in the partition of the 

 stall, and was unable to withdraw it, in consequence of the under 

 jaw catching the sides of the aperture. During the efforts to extract 

 it, so much pressure was made upon the portio dura of one side, 

 that the animal lost all power of expression in the corresponding 

 side of the head; the soft parts about the mouth dropped, and the ear 

 no longer associated with that of the opposite side in expression; yet 

 the movements of mastication and deglutition were scarcely affected. 

 This state of paralysis continued for a few days, and gradually disap- 

 peared. Fig. 204 represents a case of paralysis of this nerve, produced 



Paralysis of the Facial Nerve. (Marshall Hall.) 



1 Dissert. Inaugur, Turin., 1823; cited in Edinb. Med. and Surg. Journ., July, 1S34. 



