DIGESTION. 



191 



77. The anatomic features of the cat stomach of interest in this 



connection are represented in Fig. 78. 



These investigations show that different portions of the stomach 



walls exhibit different forms of activity, which for convenience of 



description are separately described 

 by Cannon as follows : 



i . The Movements of the Pyloric 

 Part. Within five minutes after a 

 cat has finished a meal of bread 

 there is visible near the duodenal 

 end of the antrum a slight annular 

 contraction which moves peristaltic- 

 a % to the pylorus ; this is followed 

 by several waves recurring at regu- 

 lar intervals. Two or three min- 

 utes after the first movement is seen> 

 very slight constrictions appear near 

 the middle .of the stomach, and, 



'2-Q/ J pressing deeper into the greater 



curvature, course slowly toward the 

 pyloric end. As new regions enter 



Left 



FIG. 77. SHADOW SKETCHES 

 OF THE OUTLINES OF 

 THE STOMACH OF A CAT 

 IMMEDIATELY AFTER A 

 MEAL (n.o), AND AT 

 VARIOUS INTERVALS 

 AFTERWARD (AT 12.0, AT 

 2.0, 3.30, 4.30). (W. B. 

 Cannon.) 



Post 



FIG. 78. The cardiac portion is all that 

 part to the left, as the stomach lies in the 

 body, of WX. The cardia is at C. The 

 pylorus is at P, and the pyloric portion 

 is the part between P and WX. This 

 has two divisions: the antrum, between 

 P and YZ, and the pre-antral part, be- 

 tween WX and YZ. The lesser curva- 

 ture is on the top of the outline between 

 C and P, and the greater curvature be- 

 tween the same points along the lower 

 border. (Amer. Jour, of Physiology.} 



into constriction, the fibers just previously contracted become relaxed, 

 so that there is a true moving wave, with a trough between two crests. 

 When a wave swings round the bend in the pyloric part, the indenta- 

 tion made by it deepens; and as digestion goes on the antrum 



