50 THE SURGICAL ANATOMY OF THE HORSE 



Staphylotomy 



Owing to the length and the manner of disposition of the soft 

 palate in the horse, manual exploration of the parts behind it, i.e., the 

 pharynx, guttural pouches, eustachian tubes, etc., by way of the mouth, 

 is rendered much more difficult than in most other animals. To 

 facilitate the passage of the hand into the pharynx through the isthmus 

 of the fauces in making such an examination, McKillip recommends the 

 longitudinal slitting of the soft palate — an operation to which the name 

 "Staphylotomy" is given. 



In performing this operation the animal is cast, and the jaws are 

 widely separated by means of a mouth speculum. The tongue is then 

 drawn well out of the mouth and held firmly. With the other hand a 

 knife is carefully carried through the isthmus to the posterior or free 

 border of the soft palate, when the curved cutting edge of the blade is 

 turned towards the latter, and the palate is slit along the middle line 

 from its free border to its attachment into the palatine bones, during the 

 process of withdrawing the hand. 



In this manner the roof of the isthmus is slit throughout its length, 

 which permits of the free and easy introduction of the hand into the 

 pharyngeal chamber. 



THE CESOPHAGUS 



This is a long and somewhat cylindrical membranous tube which 

 extends from the pharynx to the stomach. When not in use its lumen 

 becomes almost entirely obliterated, and its pharyngeal orifice is so small 

 that it will scarcely admit a finger-tip. This orifice is seen to be placed 

 on the floor of the pharyngeal chamber above and slightly posterior to 

 the glottis, and its mucous lining in the undilated condition of the tube 

 is seen to be very corrugated. 



It descends behind the trachea to the middle of the neck and then 



