206 



PEACTICAL PHYSIOLOGY 



curvature reaches a short distance below the level of the umbilicus. 

 The main part of the stomach is almost vertical, and is situated to the 

 left of the middle line. The pyloric end, however, passes upwards and 

 to the right across the middle line (Fig. 194). The upper limit of the 

 gastric contents is situated about 1J inches below the diaphragm, and 

 is bounded by a horizontal line, above which is the gas-containing fundus. 

 On voluntarily contracting the abdominal muscles the lower border 

 of the stomach is raised several inches, and on relaxing them it 

 generally drops an inch or two. 



FIG. 195. Diagram of shadow of stomach in the horizontal position. 



The peristaltic waves can be seen passing from the centre of the 

 greater curvature towards the pylorus. They can, however, be more 

 conveniently studied in the horizontal position. 



The examination should be continued in the horizontal position. 

 The greater curvature is now seen to have risen above the umbilicus, 

 and the clear area in the fundus is no longer visible (Fig. 195), the gas 

 having moved to the most superficial part of the stomach, corresponding 

 with which a resonant area can be marked out by percussion below and 

 to the left of the area of cardiac dulness. 



Peristalsis should now be studied in more detail. The waves start 



