CH. XXXVII.] 



MOVEMENTS OF THE STOMACH 



555 



variable; the size of the meal, its digestibility, the general state of 

 the body and mind of the individual, are all factors that influence the 

 rate of the act. The average time, however, is probably somewhere 

 about three hours. 



Dr Hertz and his colleagues at Guy's Hospital have recently 

 applied the Bdntgen ray method to man with very instructive 

 results. Large doses of bismuth oxychloride (or barium sulphate) 

 can be given to human beings without harm, and by the X-rays the 

 shadow of the opaque food can then be followed, from swallowing 

 onwards to defecation. The old ideas of the shape and position of 

 the stomach during life, which were derived from examining it in 

 the post-mortem room, are wholly incorrect. In the upright position 

 the pyloric portion is lowermost, and when food is taken it sinks 

 into this lower portion ; and above the ordinary semi-fluid contents 

 there is a horizontal upper limit above which is air. In the erect 

 position the stomach, however, is not quite vertical, but is usually 

 slightly inclined towards the right; and in the recumbent position 

 this obliquity is increased. The following three figures illustrate 

 the shape and position of the stomach when the man is erect : 

 (a) when the organ is empty; (6) when it is partly filled; and (c) 

 when it is full. 



FIG. 368. (a) View of the empty stomach in vertical position ; (b) stomach as seen soon after a 

 bismuth meal ; note the peristaltic waves at the pyloric end ; (c) view of filled stomach in vertical 

 position. (After Hertz ) 



Peristalsis, as in animals, is, during the early stages of gastric 

 digestion, limited to the pyloric portion. But the view that the 

 stomach is separated into two divisions in one of which (the fundus) 

 salivary digestion is in progress, and in other of which gastric 

 digestion proper is progressing, is quite untenable in view of these 

 observations, especially if changes of posture are occurring also. 



The fluidity of the food is another factor which is important; 

 the more fluid the food, the more rapidly does it leave the stomach. 

 If water is given to a dog with a duodenal fistula, it flows out of the 



