PANCREATIC JUICE 



217 



of smaller, spindle-shaped bodies called centro-acinar cells, the groups 

 constituting the islands of Langerhans (see Plate V, Fig. 4). It is 

 thought that these cells are not concerned in the production of pan- 

 creatic juice, but produce, by what is known as internal secretion, a sub- 

 stance taken up by the blood or lymph, which is instrumental in the 

 normal consumption of sugar. Removal of the entire pancreas is 

 followed by glycosuria, which may be relieved by transplantation 

 of parts of the pancreas in any of the tissues or even under the skin. 



20 12 19 



13 



Fig. 47. The pancreas ; its direction, relations and two excretory ducts (Sappey). 



I, first portion of the duodenum ; 2, second portion ; 3, third portion ; 4, 4, head of the pancreas ; 

 5, middle portion; 6, terminal extremity; 7, 7, principal duct; 8, accessory duct; 9, left lobe of the 

 liver; 10, right lobe; n, anterior portal eminence; 12, lobus Spigelii ; 13, antero-posterior groove; 

 14, gall-bladder; 15, hepatic duct; 16, cystic duct; 17, ductus communis choledochus; 18, trunk of 

 the portal vein; 19, coeliac axis; 20, hepatic artery; 21, coronary gastric artery; 22, cardiac portion 

 of the stomach ; 23, splenic artery; 24, spleen; 25, left kidney; 26, right kidney; 27, superior mesenteric 

 artery and vein ; 28, inferior vena cava. 



The glycolytic enzyme, however, has not been isolated. A few cases 

 of what is now known as pancreatic diabetes have been observed in the 

 human subject. The pancreas is abundantly supplied with blood. 

 The larger arterial branches ramify in the loose connective tissue be- 

 tween the lobes, into which they send twigs that break up into capillary 

 plexuses surrounding the individual acini, lying in close relation with 

 the epithelium (see Plate V, Fig. 3). 



Composition and Properties of the Pancreatic Juice. One of the 

 most ingenious of the many experiments on digestion made by Pawlow 

 is the establishment of a permanent pancreatic fistula. It is not neces- 



