CHAPTER XI. 

 DIGESTION, CONCLUDED. 



1. The Pharynx (Fig. 30) is a muscular bag lined by 

 mucous membrane; it opens at its lower end into the 

 gullet, b. Not only our food, but also the air which we 

 breathe, has to pass through the pharynx, for into its 

 upper portion, above the level of the palate, /,/, the 

 inner ends of the nostril-chambers open. Under the 

 soft palate,/, is the aperture through which food is sent 

 from the mouth; and, lower still, another opening, be- 

 hind the root of the tongue, through which air enters 

 the passage, r, which transmits it to the lungs. 



2. Swallowing or Deglutition is the process of sending 

 food or drink from the mouth to the stomach. The 

 liquid, or the mass of chewed solid food, is collected on 

 the upper surface of the tongue, and then pushed into 

 the pharynx. As soon as it has left the mouth, the 

 opening between mouth and pharynx is closed, to pre- 

 vent its return. At the same instant the soft palate 

 is raised, so as to separate the upper from the lower 

 portion of the pharynx: in this way the food is pre- 

 vented from getting into the nose. The lid, e, named 



1. What is the pharynx? What besides food passes through it? 

 What opens into it above the palate ? Below ? Behind the root of 

 the tongue? 



2. What is deglutition? How is food sent from the mouth to the 

 pharynx? How is its return prevented? How is it kept from getting 



