DEGLUTITION. 



31 



point deglutition commences, the term being applied to the 

 passage of the food and drink from the pharynx, by the gullet, 

 into the stomach. 



60. The pharynx (Fig. 23) is the cavity immediately fol- 

 lowing the mouth, and communicating with it by the isthmus. 

 It receives the food from the mouth, and the air passes by the 

 same passage when the nostrils are closed or obstructed. 

 Seven openings lead to or from this cavity, the posterior nos- 

 trils, namely, being two ; the Eustachian tubes leading to the 

 ears, two ; the opening to the mouth, one ; the opening of the 

 gullet, one ; the aperture leading to the lungs through the 

 larynx and windpipe, one ; seven in all. The trachea is the 

 tube leading into the chest, surmounted by the larynx. By 

 this tube the air passes into the lungs, placed in the thorax, 

 and the (jesophagus or gullet passes through the chest and 

 enters the abdomen to expand, as it were, into the stomach. 

 By this tube the food and drink pass into that organ. 



Pendulous Palate. 



Base of theCranium . 



Pharynx. 



(Esophagus. 



Tongue. 



Salivary Glands. 

 Lingual Bone. 



Larynx. 



Thyroid Gland. 



Trachea or "Wind- 

 pipe. 



Fig. 23. Vertical Section of the Mouth and Throat. 



61. Whilst the alimentary bolus is passing from the 

 mouth to the pharynx, the apertures of the posterior nostrils 

 are protected by the pendulous palate ; the tubes leading to 



