294 THE ABDOMEN AND PELVIS 



liver encroaches on Traube's space from the right side ; enlarge- 

 ment of the spleen encroaches on it from the left side ; and 

 pleuritic effusions encroach upon it from above. 



Structure of the Stomach. The peritoneum gives the 

 stomach a complete serous coat, except along the curvatures 

 and also over a small area which is in direct contact with the 

 diaphragm, to the left of the cardia. The muscular coat consists 

 of three layers of involuntary muscle : an outer longitudinal, an 

 intermediate circular, and an inner oblique stratum. The 

 circular layer is greatly thickened at the pylorus to form a 

 sphincter, and may, in infants, give rise to congenital stenosis 

 of the pylorus, either by continued spasm or by actual 

 hypertrophy. The mucous coat is very thick and highly vascular, 

 and it is thrown into numerous folds, save when the stomach is 

 distended. 



Radiographic Examination of the Stomach. The normal 

 stomach gives a J -shaped shadow in radiograms taken in the 

 erect posture after a bismuth meal. The longer limb of the J 

 is vertical and lies to the left of the middle line. The bismuth, 

 being supported by the tonicity of the healthy stomach wall, 

 reaches a higher level in the longer than it does in the shorter 

 limb, which corresponds to the pyloric antrum (Fig. 93). In 

 atony of the stomach this support is withdrawn, and the fluid 

 adopts a uniform horizontal level. 



In some radiograms a small cap-like shadow may be seen 

 immediately above the bismuth in the pyloric antrum and 

 separated from it by a clear area. This is due to the bismuth 

 contained in the first inch of the duodenum, and the clear area 

 corresponds to the pyloric canal, which is closed by the contraction 

 of the pyloric sphincter. 



The Examination of the Living Stomach. When the 

 abdomen has been opened, preferably in the median plane 

 above the umbilicus, the greater omentum is usually at once 

 exposed and the transverse colon may be seen shining through 

 it. The omentum is traced upwards till the greater curvature 

 is recognised, and the stomach may then be drawn downwards 

 and towards the left in order to permit the pylorus and the first 

 part of the duodenum to be examined. In the healthy stomach 

 the walls are firm, and the muscular thickening which marks the 

 pyloro-duodenal junction renders its recognition easy ; but in the 

 atonic stomach the walls are flaccid and thinner, and the pylorus 

 is more difficult to identify. In these cases the pyloric veins 



