404 



THE DIGESTIVE SYSTEM 



gland and supply capillaries to the intralobular connective tissue about 

 the acini. Certain arterial branches also enter -the islets and form a 

 specially"rich plexus of broad capillaries^ ( sinusoids ) within these cell 

 groups. The veins return the islet blood by a similar course. 



The Lymphatics. 

 The lymphatics are' 

 mostlyjconfined to the 

 interlobular tissue; 

 where they are in re- 

 lation with the blood- 

 ves~sels7"~ 



The Nerves. The 

 nerves are derived 

 from the sympathetic 

 system, and occur as 

 small trunks within 

 tnlTlnterlobular con- 

 nective tissue. . Nu- 

 merous small ganglia 

 occur in their course. 

 As in the salivary 

 glands the nerves sup- 

 ply the vascular walls. 

 About_JJije~secreting 

 acini they form a del- 

 icate network of 

 naked fibrils, from 

 which end branches 

 penetrate Hre"~~base- 

 ment membrane and 

 terminate upon, the 

 secreting cells. Lam- 

 ellar corpuscles are oc- 

 casionally found in the interlobular connective tissue of the pancreas. 

 Resume. Finally the attention of the student should be specially 

 directed to the presence of the pancreatic islets, the centro-acinar cells, 

 the very distinct inner granular and outer fibrillar zones of the secreting 

 cells, the thick walls of the interlobular ducts, the absence_ofjfl.tralobular 

 ducts except of the intercalary type, and the loose character of the inter- 

 lobular tissue as the distinguishing characteristics of the pancreas. 



FIG. 377. SECTION OF A PANCREATIC ISLET FROM 

 INJECTED SPECIMEN OF CAT'S PANCREAS TO SHOW 

 THE PROFUSE BLOOD SUPPLY. 



The capillaries were accurately drawn by aid of a 

 camera lucida. Only the nuclei of the islet cells are 

 indicated; one acinus is shown at the left. X 500. 



