THE DIGESTION OF FOOD 



109 



154. The Gullet. The gullet, or food pipe, is a tube about 

 nine inches long, hanging loosely behind the windpipe. Its 

 thick walls are provided with hooplike muscles which con- 

 tract with a wavelike motion, well seen when a horse is 



B A 



FIG. 70. BLACKBOARD SKETCH. 



The Stomach. 

 A, cardiac end ; B, pyloric end. 



drinking water, and so push the food along towards the 

 stomach. The pellet of food is pushed downwards by 

 these muscles 1 in some such way as we would push any 

 substance along inside of a rubber tube (Fig. 83). 



Experiment 33. Place the fingers on the "Adam's apple" (Sec. 

 379). Pretend to swallow something, and you can feel the upper 

 part of the windpipe and get a very fair idea of the action of the 

 epiglottis and the closing of its lid, thus covering the entrance and 

 preventing the passage of food into the windpipe. 



1 It is important to remember that, in swallowing, the food and drink 

 do not simply fall down the gullet. Their passage is controlled by the 

 muscles in such a way that they grip successive portions swallowed, and 



