SECTION II 



THE PASSAGE OF FOOD FROM THE MOUTH 

 TO THE STOMACH 



THE food after mastication is carried to the stomach by a complex 

 series of co-ordinated movements involving the muscles of the pharynx 

 and the oesophagus (Fig. 330). Various methods have been used to 



FIG. 330. Dissection to show muscles employed in deglutition. 

 6, styloid process, from which arise 1, the styloglossus, 2, the stylohyoid, 

 A, the stylo-pharyngeus muscles ; c, section of lower jaw ; d, hyo'id bone 

 e, thyroid cartilage ; g, isthmus of thyroid gland ; 4, cut edge of mylohyoid 

 muscle ; 5, 67, 8, muscles of tongue ; 9, 10, 11, superior, middle, and inferior 

 constrictors of pharynx ; 12, oesophagus. (ALLEN THOMSON.) 



study the process of deglutition in man and the higher animals. 

 Important information can be obtained by allowing a man or animal 

 to swallow either a fluid or solid with which bismuth is mixed and 

 observing the passage of the opaque substance under the Rontgen 



758 



