394 THE DIGESTIVE SYSTEM 



THE PANCREAS 



The pancreas is a flalreleBgate body lying behind the stomach be- 

 tween the loop of the duodenum and the spleen. It arises as two anlages : 

 a smaller from the common bile duct (ventral pancreas), and a larger 

 from the duodenum (dorsal pancreas). These subsequently fuse to form 

 a single organ drained mainly by the duct of the Central component, 

 which has meanwhile made an anastomosis with thatj'of the dorsal com- 

 ponent, the latter proximal to the anastomosis nevertheless commonly 



FIG. 365. EARLY STAGES IN THE DEVELOPMENT OF THE PANCREAS, ILLUSTRATING 

 CONDITIONS IN THE 5 AND 7 WEEKS OLD HUMAN EMBRYOS. 



Dp, dorsal pancreas; Vp, ventral pancreas; Pd, pancreatic (Wirsung's) duct; 

 Apd, accessory pancreatic (Santorini's) duct; Dch, duct us choledochus; cd, cystic 

 duct; Hd, hepatic duct. (Adapted from Kollman.) 



remaining pervious and functional. The pancreas! bears a close struc- 

 tural resemblance to the salivary glands, more especially the parotid. 

 It is a compound tubulo-acinar gland which contains an immense num- 

 ber of small lobules associated into lobes and which pours its secretion 

 into the lumen of the duodenum by means of the chief (Wirsung's) 

 and accessory (Santorini's) pancreatr<rchicts. The lobules are united by 

 a delicate and relatively very loose fibro-elastic connective tissue. 



The ducts of the pancreas branch ^nd arborize in the same manner as 

 those of the ^sali^a^L-glands. The interToBular" ducts are lined by a 

 single layer of columnar cells; in the larger divislotis (interlobar ducts) 

 occasional goblet cells are found. The wall of the interlobular pan- 

 creatic ducts is much thicker than in those of the salivary glands, for 



