MASTICATION" AND DEGLUTITION, 



formed in very rapid succession, and require but a short space of 

 time. 



*' Nature has provided various contrivances for opening and 

 securing this passage. 1 " 



The important motion of the tongue is regulated by the os 

 hyoides. 



" The smallest particle of food is prevented from entering the 

 nostrils or Eustachian tubes, by means of the soft palate 8 , which, 

 as well as the uvula suspended from its arch, and whose use is 

 not clearly understood, is extended by muscles of its own, and 

 Closes those openings. l 



" The tongue protects the glottis, for the larynx at the mo- 

 ment of deglutition is drawn upwards and forwards, and in a 

 manner concealed under the retracted root of the tongue, and 

 applied to the latter in such a way, that the glottis, being also 

 constricted, and protected by the epiglottis, is most securely 

 defended from the entrance of foreign substances." The glottis, 



POSTERIOR VIEW. 



LATERAL VIEW. 



Posterior and lateral views of the throat, a, the tongue : b, palato-staphyline 1 

 muscles, forming the uvula : c, epiglottis : d, larynx : e, pharynx : /, beginning 

 of oesophagus : g, constrictor superior of pharynx turned back : h, constrictor 

 medhis : i, constrictor inferior : j, posterior opening of nostrils : k, opening of 

 Eustachian tube : I, genio-glossus muscle : ra, buccinator : n, orbicularis labi- 

 orum : o, cavity of the nostrils. 



r ' J. C. Rosenmuller, Icones Chirurgico-Anatomicce. Fasc. !. Vinar. 1805. 



foi." 



* " Littre, MSm. de VAcad. des Sc. de Paris, 1718. tab. xv." 

 1 " Santorini, Tab. Posthum. iv vi, fig. 2. and vn. 



B. S. Albinus, Tab. Muscular, xii, fig. 11. 27, 28. V A. -' .' 



