DEGLUTITION. 



309 



coming together, lie together like side-screens or curtains (Landois), 

 meet the raised dorsum of the tongue, and so form a partition between 

 the mouth and pharynx ; the occlusion is still further assisted by the 

 contraction of the stylo-glossi muscles, which elevate the tongue and 

 press it against the palate. 



The second stage of deglutition then commences, and the bolus of 

 food is now entirely beyond the control of the will, and must pass down 

 the pharynx into the oesophagus, its ejection into the mouth again only 



Fig. 130.— Position op the Soft Palate duhing the Second Stage of 



the Act of Deglutition, after Fiabx. (Mayer.) 



A, soft palate; C, bolus; E. orifice of Eustachian tube; B, tongue; G, pharynx; H, epiglottis; I, (esophagus. 



being rendered possible by an active coughing or gagging movement. 

 Its downward movement during this stage, which lasts while the food is 

 passing from the anterior pillars of the fauces to the entrance of the 

 oesophagus, is still attended by sensation. 



The muscular movements of the second stage of deglutition are much 

 more complex than in the first. The pharynx communicates with three 

 cavities, — the posterior nasal chamber, the oesophagus, and the larynx. 

 Special mechanisms exist which direct the food downward toward 



