DIGESTION OF FOOD. 333 
of food or drink entering the windpipe produces a perfect 
storm of excitement in the respiratory system. The food, there- 
Fie. 281.—Cavities of mouth and pharynx, etc. (after Sappey). Section, in median line, of 
face and superior portion of neck, designed to show the mouth in its relations to the nasal 
fossse, pharynx, and larynx: 1, sphenoidal sinuses; 2, internal orifice of Eustachian tube; 
3, palatine arch ; 4, velum pendulum palati ; 5, anterior pillar of soft palate ; 6, posterior 
pillar of soft palate ; 7, tonsil ; 8, lingual portion of cavity of pharynx ; 9, epiglottis ; 10, 
section of hyoid bone ; 11, laryngeal portion of cavity of pharynx ; 12, cavity of larynx. 
fore, when it reaches the esophagus, must be kept, on the one 
hand, from entering the nasal, and, on the other, the laryngeal 
openings. This is accomplished as follows: When the food has 
been gathered into a bolus on the back of the tongue, the tip of 
this organ is pressed against the hard palate, ‘by which the 
mass is prevented from passing forward, and, at the same time, 
forced back into the pharynx, the soft palate being raised and 
the edges of the pillars of the fauces made to approach the 
uvula, which fills up the gap remaining, so that the posterior 
nares are closed and an inclined plane provided, over which 
the morsel glides. The after-result is said to depend on the 
size of the bolus. When considerable, the constrictors of the 
