THE MOUTH AND THROAT. 



107 



affected from middle ear disease or neuritis. When paralyzed, the muscles of the 

 lips, both upper and lower, on the affected side, droop. The drooping of the lower lip 

 may allow the saliva to run out of the mouth. It is also impossible for the patient 

 to pucker his mouth, as in whistling. If the lesion of the facial nerve is inside the 

 skull and not in the Fallopian canal, the great petrosal nerve and some of the palatal 

 muscles will be paralyzed, the voice will be altered and swallowing interfered with. 



The depressor labii inferioris instead of receiving its nerve supply from the supra- 

 mandibular branch of the facial, frequently is supplied by the inframandibular branch; 

 pressure or injury of this branch in enlargements of or operations on the submandib- 

 ular lymph-nodes has produced paralysis of the muscle with a peculiar alteration of 

 the facial expression, well shown (see Fig. 132) by a case of Dr. McDowd (Annals of 

 Surgery, July, 1905). 



Mouth. Surface Anatomy. In looking into the mouth, one sees the tongue 

 below and the roof above, surrounded in front and on the sides by the teeth. On each 

 side are the inner surfaces of the cheeks and posteriorly are seen the uvula, the 



Hard palate 



Junction of the hard 

 and soft palates 



Soft palate 



Uvula 



Anterior pillar of fauces 



Posterior pillar of fauces 



Tonsil 



FIG. 133. Interior of the mouth. 



arches of the palate, and the pharynx. On the mucous membrane of the cheek, 

 opposite the second upper molar tooth, is a small papilla in the top of which opens 

 the duct of the parotid gland. A small probe can be inserted into it and passed 

 outward and backward toward the gland. 



Tongue. The tongue is covered with a mucous membrane which is modified 

 skin; therefore it is subject to the same diseases as the skin. It is covered with 

 papillae of three kinds the filiform, fringiform, and circumvallate. The filiform 

 are the smallest and most numerous and form a sort of ground-work in which the 

 others are imbedded. The fungiform are larger and fewer in number and are scattered 

 on the dorsum, sides, and tip of the tongue among the filiform. The circumvallate, 

 seven to twelve in number, form a V-shaped row at the base of the tongue. In the 

 eruptive fevers, particularly scarlet fever, the tongue gets very red and the papillae 

 become enlarged, forming what is known as the strawberry or raspberry tongue. 

 Just beyond the apex of the circumvallate papillae in the median line is the foramen 

 c&cum. It is sometimes patulous for a short distance and is the upper extremity of 

 the remains of the thyroglossal duct. 



