502 DISEASES OF THE INSULAR APPARATUS OF THE PANCREAS 



according to Vierordt varies between 85 gm. and 105 gm., according to Orth 

 between 90 gm. and 120 gm. The pancreas is extraordinarily well vas- 

 cularized. It receives a large branch (arteria pancreatico-duodenalis supe- 

 rior) from the ramus gastroduodenalis of the hepatic artery, further several 

 branches from the splenic artery, and one branch (arteria pancreatico-duo- 

 denalis inferior) from the superior mesenteric artery. The pancreas is sup- 

 plied by an abundant nerve plexus of branches from the vagus and from the 

 sympathetic fibers that emanate from the sympathetic trunks or from the 

 great sympathetic ganglia. 



The glandular acini of the pancreas form large lobes bound together by 

 loose connective tissue that are in turn made up of smaller lobules. The 

 excretory ducts of the acini unite in the pancreatic duct or duct of Wirsung, 

 which empties in common with the ductus choledochus into the papilla of 

 Vater in the duodenum. A large excretory du'ctus pancreaticus accessorius, 

 emanating from the head, unites with the duct of Wirsung. From the acces- 

 sory duct there usually branches a duct uniting with the duodenum (ductus 

 Santorini). Opie found this duct obliterated or markedly narrowed in 

 numerous cases. Only in such cases was the secretion of the pancreas fully 

 cut off from the intestine by closure of the principal duct. The closure of 

 the accessory duct may lead to isolated sclerosis of the head of the pancreas. 

 Further, we should consider that not infrequently accessory lobules of the 

 pancreas are found in the duodenum. 



In the lobules of the glandular parenchyma are found imbedded between 

 the individual acini cell groups that consist in polygonal cells with large round 

 nuclei. These cells stain less distinctly than the cells of the acini. The pro- 

 toplasm is lighter, it does not show the Distinct zymogen-granules as does the 

 glandular tissue. These cell groups, which occur in very different number 

 and size, are named after their discoverer, the island of Langerhans. They 

 are found in all kinds of animals (Diamare) , and in some they are very large 

 and even visible macroscopically. They show an especial abundance of 

 blood-vessels. The capillaries form a dense network interlarding the ceU 

 groups similar to what we see in the renal glomerules (Kuhne and Lea} . The 

 cell accumulations have no connection with the excretory ducts of the gland. 

 They are never filled after the injection of the excretory ducts (v. Ebner). 

 Many histologists state that the islands of Langerhans are surrounded by a 

 capsule (Renaut, Opie, Flint, and others}. Others combat the existence of a 

 capsule (Diamore, Hansemann, and others) . At any rate it should be men- 

 tioned that in many species of animals (for example in the cartilaginous fishes) 

 the capsules are found constantly (Rennie). 



Very different views have been expressed as to the nature of these pic- 

 tures. Langerhans regarded them as nervous structures, later authors as 

 lymph follicles. Finally the view was promulgated that they constitute a 

 gland with internal secretion distributed throughout the entire pancreas, 

 that gives off an internal secretion to the interlarding capillary network. 



