448 



The Pancreatic Ducts in the Doo; 



Obsekvations. — Pancreatic Orifices. Figs 5 and 6. There are two 

 pancreatic orifices in the dog. One is in or close beside the terminal 

 part of the ductus choledochus, this relation identifying it as the opening 

 of the ductus Wirsungianus. It is about 0.3 mm. in diameter and is 

 situated on the summit of a papilla in the mucosa of the dorsal wall of 

 the duodenum, 3-5 cm. from the pylorus. It looks either into the 

 ductus choledochus near the opening of the latter or caudalward on the 

 free surface of the papilla, about 2 mm. from the bile- opening. In one 

 instance celloidin injected into the bile-duct towards the bowel passed 

 freely into the ductus Wirsungianus, having first closed the common 

 orifice by precipitating in it.'* 



The other pancreatic 

 orifice is about 0.8 mm. 

 in diameter, and is situ- 

 ated at the summit of a 

 similar but smaller pap- 

 illa 2-5 cm. caudosinis- 

 tralward from the first. 

 This is the opening of the 

 ductus Santorini, distin- 

 guished by its isolation 

 from the bile-duct. 



These orificial papillae 

 are 3-5 mm. high and are 

 really the enlarged ter- 

 minal part of ridges of 

 the mucosa due to the 

 duodenal parts of the 

 ducts. Each ridge begins cranialward, culminates and terminates 

 Caudalward in the papilla. That nearer the pylorus is 7-10 mm. long 

 and 2-3 mm. wide, and runs caudo-dextralward. The other is about 

 5 mm. long, 2 mm. wide and runs caudo-sinistralward. 



The crests of the ridges and especially of the papillae are usually 

 reddish owing to congestion of the blood-vessels there. The anterior 

 papilla is often bilestained. 



The real form of the papillae and ridges is seen only in sections of 

 the duodenum. Fig. 7. As the bowel contracts, the ridges enlarge 

 and numerous false rugae appear. 



2 This simulates injection of the pancreas by bile when the common orifice is 

 obstructed by a gallstone. 



Fig. 5. 



Fig. 6. 



Fig. 5 Part of dorsal wall of dog's duodenum, 



with orificial papillae, A, of ductus choledochus; 

 B, of ductus Santorini. The bowel-wall was con- 

 tracted and the mucosa much wrinkled. 



Fig. 6. — Dorsal wall of dog's duodenum and orifi- 

 cial papillae. C, orifice of ductus choledochus; W, 

 of ductus Wirsungianus; S, of ductus Santorini. 

 The bowel-wall was relaxed. 



