FACIAL NERVE, OR NERVE OF EXPRESSION. 625 



and the palato-pharyngeus, without any connection with the glosso-pharyngeal nerve. 

 In our anatomical description of the branches of the facial, we have already noted a 

 filament, described by Hirschfeld, which passes to the stylo-glossus and palato-glossus 

 muscles. This is the filament affected in deviation of the point of the tongue. 



In view of the pathological examples of paralysis of the palate and uvula in certain 

 cases of facial palsy, the frequent occurrence of contractions of the muscles of these 

 parts upon galvanization of the facial, and the reflex action through the glosso-pharyn- 

 geal and the facial, there can be little doubt that the muscles of the palate and uvula are 

 animated by filaments derived from the seventh nerve. The effects of paralysis of these 

 muscles are manifested by more or less difficulty in deglutition and in the pronunciation 

 of certain words, with great clifficulty in the expulsion of mucus collected in the back 

 part of the mouth and the pharynx. 



Functions of the External Branches of the Facial. The general function of the 

 branches of the facial going to the superficial muscles of the face is sufficiently evident, 

 in view of our present knowledge of the distribution of these branches and the general 

 properties of the nerve. Throughout the writings of Sir Charles Bell, the facial is 

 spoken of as the " respiratory nerve of the face." It is now recognized as the nerve 

 which presides over the movements of the superficial muscles of the face, not including 

 those directly concerned in the act of mastication. This being its general function, it is 

 easy to assign to each of what may be termed the external branches of the facial its 

 particular office. 



Just after the facial nerve has passed out at the stylo-mastoid foramen, it sends to the 

 glosso-pharyngeal the communicating branch, the functions of which we have just con- 

 sidered in connection with the movements of the palate. 



The posterior auricular branch, becoming sensitive by the addition of filaments from 

 the cervical plexus, gives sensibility to the integument on the back part of the ear and 

 over the occipital portion of the occipito-frontalis muscle. It animates the retrahens 

 and the attollens aurem, muscles but little developed in man, but very important in cer- 

 tain of the inferior animals. It also animates the posterior portion of the occipito-fron- 

 talis muscle. 



The branches distributed to the posterior belly of the digastric and to the stylo-hyoid 

 muscle simply animate these muscles, one of the uses of which is to assist in deglutition. 

 The same may be said of the filaments that go to the stylo-glossus. 



The two great branches distributed upon the face after the trunk of the nerve has 

 passed through the parotid gland have the most prominent function. Both of these 

 branches are somewhat sensitive, from their connections with other nerves, and are dis- 

 tributed in small part to integument. 



The temporo-facial branch animates all of the muscles of the upper part of the face. 

 In complete paralysis of this branch, the eye is constantly open, even during sleep, from 

 paralysis of tho orbicularis muscle. In cases of long standing, the globe of the eye may 

 become inflamed from constant exposure, from abolition of the movements of winking by 

 which the tears are distributed over its surface and little foreign particles are removed, 

 and, in short, from absence of the protective action of the lids. In these cases, the 

 lower lid may become slightly everted. The frontal portion of the occipito-frontalis, 

 the attrahens aurem, and the corrugator supercilii muscles, are also paralyzed. The 

 most prominent symptom of paralysis of these muscles is inability to corrugate the brow 

 upon one side, as in frowning. 



Paralysis of the muscles that dilate the nostrils has been shown to have an important 

 influence upon respiration through the nose. It was the synchronism between the art- 

 of dilatation of the nostrils and the movements of inspiration which first led Sir Charles 

 Bell to regard the facial as a respiratory nerve. In instances of complete paralysis of 

 the nostril of one side, there is frequently some difficulty in inspiration. Sir Charle 8 

 Bell refers to a case in which, when " the patient lay with the sound side against the 

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