THE MOUTH AND THROAT. 



119 



4 cm. long, 2.5 cm. being cartilaginous (pharyngeal portion) and 1.5 cm. being 

 bony. At the junction of the bony and cartilaginous portions the lumen is slightly 

 diminished, forming the isthmus. The tube runs upward, backward, and outward. 



The mucous membrane of the throat is continuous with that lining the tube and 

 tympanum, therefore inflammation of the pharynx travels up the tube and affects the 

 middle ear. This is the manner in which earache or inflammation and suppuration 



FIG. 148 Rhinoscopic mirror in position. A view FIG. 149. Palpation of the posterior nares and phar- 

 can be obtained of the vault of the pharynx and poste- yngeal tonsil, 



rior nares. 



of the middle ear is produced. This also explains why impairment of hearing so 

 often accompanies or follows sore throat. When the tube is in a healthy condition, 

 the air finds free access to the ear, in swallowing, sneezing, etc. This is readily 

 demonstrated by closing the nostrils and swallowing, when the pressure of air out- 

 side the ear drum will be distinctly felt. When inflammation affects the lining mem- 



Vault of pharynx 



Superior turbinats 



Septum 



Middle turbinate 



Mouth of Eustachian tube 



Inferior turbinate 



FIG. 150. View of posterior nares in the pharyngeal mirror. 



brane it swells and blocks up the tube and prevents the free access of air to the ear. 

 If the swelling is not too great, air can be forced from the throat to the ear by three 

 different means. The distention of the middle ear by air is called inflating it. The 

 method of Valsalva consists in holding the nostrils and mouth shut and blowing. 

 If the air enters the middle ear, the tympanic membranes will be felt to bulge 

 outward. The method of Politzer is to have the patient hold a small quantity of 



