364 CLINICAL APPLIED ANATOMY. 



is in relation with the greater sac. Duodenal ulcer, however, 

 like gastric ulcer, does not tend to perforate into the lesser sac 

 and probably for similar reasons, i.e., the formation of adhesions 

 which obliterate the small posterior diverticulum. Ulcers of the 

 first part have, however, a great tendency to perforate anteriorly 

 into the greater sac and to produce either general peritonitis or 

 a localised collection of pus in the right kidney pouch or 

 subphrenic space. Various vessels have been known to be 

 eroded. Posteriorly the portal vein, the hepatic artery, or its 

 gastro-duodenal branch may suffer. The superior pancreatico- 

 duodenal branch of the latter has been perforated, and ulceration 

 has been known to extend sufficiently to the left to open branches 

 of the splenic artery, and even the aorta. (Fig. 52, p. 416.) 



The second part of the duodenum is sometimes the site of 

 ulceration, which is usually above the level of the biliary papilla. 

 This part lies on the right side of the spine, and reaches as low 

 as the third or even the fourth lumbar vertebra. The transverse 

 colon crosses its middle ; it comes into contact above with the 

 neck of the gall bladder and below with the coils of small 

 intestine ; any of these may be opened by an ulcer, and a bi- 

 mucous fistula result. Posteriorly it is in relation with the 

 inner part of the right kidney, with its vessels and ureter; but 

 these are not known to suffer. Moulded on its right or convex 

 aspect is the duodenal impression of the liver, and below this the 

 hepatic flexure of the colon. Its concave left aspect is closely 

 applied to the head of the pancreas, and is in intimate relation 

 with the bile and pancreatic ducts, the papilla of Vater, or 

 common orifice of these ducts, being found three and a half or four 

 inches beyond the pylorus. Ulcers near the papilla are of especial 

 importance, since they may cause complete cicatricial occlusion 

 of both the bile and pancreatic ducts, giving rise to very 

 characteristic symptoms. The inferior vena cava is in close 

 relation with the duodenum behind the head of the pancreas. 

 The second part of the duodenum is only covered by peritoneum 

 in front and on its convexity. When there is no transverse 

 mesocolon, the transverse colon may be in direct contact over a 



