1 82 THE ENGINES OF THE HUMAN BODY 



channel we have been examining in the previous chapter. 

 In the stomach of our friend we can see the same kind 

 of constriction rings appear and move ; they do not 

 begin at the upper end of the stomach, but below 

 its middle part (fig. 39). We see one of these rings 

 gradually form and then move slowly towards our 



EPIGASTRIUM^ 

 COSTAL MARGIN 



PYLORIC PART 

 of STOMACH 



OESOPHAGUS 



PYLORUS 

 DUODENUM 



AIR CAP 

 in FUNDUS 

 of STOMACH 



BODY of 

 STOMACH 



(under- Ribs) 



BODY of 

 STOMACH 



(exposed J 



END of 

 DUODENUM 



UMBILICUS 

 PELVIS 



Fig. 39. — An X-ray shadow of the full stomach, with contraction waves 

 passing towards the pylorus. 



patient's right, thus approaching the pyloric gateway of 

 his stomach. The constriction ring pushes in front of 

 it a dilatation wave as if it were urging or milking the 

 contents of the lower part of the stomach towards the 

 pyloric gateway. We notice, too, that very soon after 

 one wave has set out another begins almost at the same 

 point, and pursues its forerunner at an orderly pace ; 

 there is a constant succession of these constriction waves ; 

 there may be as many as three seen in progress at the 



