LUMBAE ABSCESS. 387 



the former case and depressed in the latter. The subdia- 

 phragmatic region may be almost entirely shut off from the rest 

 of the peritoneal cavity in consequence of adhesion of the great 

 omentum to the anterior abdominal wall. The upper part may 

 also be shut off by adhesions between the abdominal wall and 

 the liver or stomach. 



The Lumbar Regions. These regions communicate below 

 with the pelvis. With the body supine they form inclined 

 planes leading from the pelvic brim to the subdiaphragmatic 

 space. Their separation from the latter is very incomplete. 

 On the left side the phrenico-colic fold, and on the right a 

 similar but more variable fold may form more or less effectual 

 barriers. As the result of appendix suppuration pus may track 

 upwards in the right loin, between the colon and the parietes, 

 and infect the right kidney pouch or extend between the liver 

 and the diaphragm. Even suppuration of pelvic origin may 

 travel the same way. Conversely, suppuration in connexion 

 with perforated pyloric or duodenal ulcers may be directed by 

 the mesocolon and prominence of the spine into the kidney 

 pouch, and then travel downwards in the right lumbar region 

 simulating appendicitis. Lesions of the gall bladder may produce 

 a similar result. 



When perforation of the anterior wall of the stomach has 

 given rise to a collection of fluid in the greater sac around the 

 spleen, a well developed phrenico-colic fold may effectually 

 seal off the infection from the left lumbar region. A badly 

 developed fold may allow the lumbar region and even the pelvis 

 to be infected. Pelvic collections and infections may travel 

 upwards by the same route, following the descending colon. 



The Submesocolic Region lies between the transverse meso- 

 colon and the mesentery of the small intestine. Its apex lies at 

 the point of convergence of these folds near the second lumbar 

 vertebra. The prominence of the spine causes this region to 

 slope away towards the right loin, with which region it is 

 virtually continuous. The combined areas contain coils of small 

 intestine, the caecum, ascending colon, lower part of the right 



252 



