ABDOMINAL CAVITY 503 



lower and medial part of the gastric concavity of that organ 

 (Fig. 197, p. 512). 



Dissection. To display the posterior relations of the body and neck of 

 the pancreas raise the tail from the spleen then, working from left to right, 

 carefully separate the body and the neck from the structures which lie 

 behind them. 



The posterior surface of the body of the pancreas lies, in 

 front of the middle portion of the left kidney ; in front of the 

 hilus of the kidney and the structures which pass through 

 it in front of the lower part of the left suprarenal gland ; 

 in front of the left crus of the diaphragm ; and it joins the 

 left and anterior end of the neck in front of the left border 

 of the aorta. The splenic vein runs behind its upper border, 

 between it and the kidney and the left suprarenal gland, to the 

 back of the neck, where it joins with the superior mesenteric 

 vein to form the commencement of the portal vein. The 

 inferior mesenteric vein passes behind the right end of the 

 posterior surface to join the splenic vein, and the left internal 

 spermatic vein also ascends behind it to join the left renal vein 

 which issues from the hilus of the kidney and passes to the right 

 to join the inferior vena cava behind the head of the pancreas. 



Ducts of the Pancreas. The ducts of the pancreas are, as 

 a rule, two in number a main duct and an accessory duct. 

 Both run within the gland substance. 



The main pancreatic duct of Wirsung begins at the tail of 

 the gland by the union of the small ducts issuing from the 

 lobules in this region, and it proceeds transversely towards 

 the right. It gains considerably in size as it traverses the 

 organ from its being joined by the small ducts which come 

 from the various groups of lobules. Reaching the neck 

 of the gland it bends downwards into the substance of the 

 head. If the gland is divided horizontally, little difficulty will 

 be experienced in discovering the main duct. The extreme 

 whiteness of its walls is a help to the student in this dissection. 

 Close to the duodenum the pancreatic duct comes in contact 

 with the common bile-duct, and, in company, both pierce the 

 coats of the descending part of the duodenum upon its posterior 

 and medial aspect, and terminate in its wall in a dilatation, 

 the ampulla of Vater, which opens into the cavity of the 

 duodenum at the apex of a papilla, the papilla duodeni. 



The accessory duct of Santorini is small, and arises in the 

 lower part of the head of the gland. It usually has an 



