82 SURGICAL APPLIED AXATOMV. [Chap. v. 



and thus impairment of hearing may follow upon great 

 thickening of the mucous membrane of the tube due 

 to the extension of inflammatory mischief from the 

 pharynx. In the deafness associated with enlarged 

 tonsils, and post-nasal growths, the hypertrophic 

 change extends to the mucous lining of the tube, and 

 in the cases of many pharyngeal growths and nasal 

 polypi, the orifice of the tube is mechanically ob- 

 structed. The near relation of the pharyngeal end of 

 the tube to the posterior nares serves to explain a case 

 where suppuration in the mastoid cells followed upon 

 plugging of the nares for epistaxis. A probe passed 

 up the Eustachian tube from the pharynx would hit 

 the joint between the incus and the stapes, and would 

 then enter the mastoid cells (Tillaux). 



The upper edge of the pharyngeal orifice of the 

 tube is about half an inch below the basilar process, 

 half an inch in front of the posterior wall of the 

 pharynx, half an inch behind the posterior end of 

 the inferior turbinated bone, and half an inch above 

 the soft palate (Tillaux). In the fetus the orifice is 

 below the hard palate : at birth on the same level. 

 The form of the opening is that of a triangle. The 

 opening of the tube is effected by the tensor palati, 

 levator palati, and salpingo-pharyngeus. 



Just behind the elevation formed at the orifice of 

 the Eustachian tube there is a depression in the wall 

 of the pharynx, known as the fossa of Roscnmiiller. 

 It may be mistaken for the orifice of the tube, and 

 may readily engage the point of an Eustachian cath- 

 eter. In cases in which the pharyngeal tonsil (Luscha's 

 tonsil) is enlarged, this fossa on either side may be 

 greatly deepened and made to form a narrow diverti- 

 culum. (See page 133.) To pass the Eustachian catheter, 

 the instrument is carried along the floor of the nares 

 with its concavity downwards, " until its point can be 

 felt to drop over the postei'ior edge of the hard palate 



