THE PHAKYNX. 



THE PHARYNX. 



20t 



Proceeding to the back of the mouth, we find the pharynx {carrying or 

 conveying the food towards the stomach). It commences at the root of the tongue 

 (see 7, 8, and 9, p. Ill) ; is separated from the mouth by the soft palate (7), 

 which hangs down from the palatine bone at 8, and extends to the epiglottis or 

 covering to the windpipe. When the food has been sufficiently ground by the 

 teeth, and mixed with the saliva, it is gathered together by the tongue, and 

 by the action of the cheeks and tongue, and back part of the mouth, forced 

 against the soft palate, which, giving way, and being raised upwards towards the 

 entrance into the nostrils, prevents the food from proceeding that way. It passes 

 to the pharynx, and the soft palate again falling down, prevents its return to 

 the mouth, and also prevents, except in extreme cases, the act of vomiting in 

 the horse. Whatever is returned from the stomach of the horse, passes through 

 the nose, as the cut will make evident. 



The sides of the pharynx are lined with muscles which now begin power- 

 fully to contract, and by that contraction the bolus is forced on until it reaches 

 the gullet (10), which is the termination of the pharynx. Before, however 

 the food proceeds so far, it has to pass over the entrance into the windpipe 

 (3), and should any portion of it enter that tube, much inconvenience and 

 danger might result ; therefore, this opening is not only lined by muscles 

 which close it at the pleasure of the animal, but is likewise covered by 

 a heart-like elastic cartilage, the epiglottis (2), with its back towards the 

 pharynx, and its hollow towards the aperture. The epiglottis yields to the 

 pressure of the bolus passing over it, and lying flat over the opening into the 

 windpipe, and prevents the possibility of anything entering into it. No sooner, 

 however, has the food passed over it, than it rises again by its own elasticity, 

 and leaves the upper part of the windpipe once more open for the purpose of 

 breathing. The voice of animals is produced by the passage of air through 

 this aperture, communicating certain vibrations to certain folds of the 

 membrane covering the part, and these vibrations being afterwards modified 

 in their passage through the cavities of the nose. In order to understand 

 the diseases of these parts, the anatomy of the neck generally must be 

 considered. 



plight. While purulent matter is issuing in relief, so far as the breathing is concerned, 



profusion from his swollen nostrils, and slaver may be obtained from the operation of bro/i- 



fuauis out from between bis tumefied lips, it chotomy, yet, from the pain and irritation he 



is distressing to hear the noise that he makes is suffering, added to the impossibility of 



in painful and laboured efforts to breathe, getting aliment into his stomach, he must 



Thorc is imminent danger of suffocation in speedily Bink to rise no more." — Vetcrina- 



sueli a caso as tbis ; mid even although some rian, vol. vi, p. CI 1 . 



