2O 



APPLIED PHYSIOLOGY 



been chewed to a paste, it is collected into a mass upon 

 the back of the tongue, and pushed into a muscular bag 

 called the pharynx. The pharynx has seven openings. 

 Two into the nose and two into the ears can be closed by 

 raising the back part of the roof of the mouth. An open- 

 ing into the windpipe 

 can be closed by a cover 

 called the e^lottis. The 

 opening into the mouth 

 can be closed by two 

 curtains, which slide 

 across the back of the 

 tongue and meet in the 

 middle. The opening 

 into the tube leading to 

 the stomach is the only 

 one left. When food 

 reaches the pharynx, its 

 muscles squeeze the food 

 into the open tube lead- 

 ing to the stomach. 

 Thus food is swallowed. 

 28. The esophagus. 

 The tube leading from 

 the pharynx to the stom- 

 ach is called the esoph- 

 agus. The esophagus 

 that it is forced in the direction 

 of water in a horse's 



Diagram of the beginning of swallowing. 



a top of tongue. 



b pharynx. 



c morsel of food. 



d sliding door of the front of the pharynx. 



e soft palate. 



/ epiglottis. 



squeezes the food so 



of the stomach. Each swallow 



esophagus can be seen to run up its neck on its way to the 



stomach. Man's esophagus would look the same if it were 



near the surface. 



29. The stomach. The inside of the body is divided 



