230 



HISTOLOGY. 



PANCREAS. 



The pancreas is a large entodermal gland consisting of lobes and 

 lobules and resembling in its general structure the parotid gland. It arises 



as two distinct out- 

 growths of the di- 

 gestive tract, as seen 

 in Fig. 261, A. 

 The smaller of 

 these, called the 

 ventral pancreas, de- 

 velops from the 

 ductus choledochus 

 near its intestinal 



FIG. 261. A, DIAGRAM OP THE PANCREAS PROM A 15 MM. HUMAN EM- orifice. Its duct 



BRYO. B, DISSECTION OP THE DUODENUM AND PANCREAS OP AN 



ADULT. (After Schiomer.) Called the panCTe- 



a. p. d., Accessory pancreatic duct; c. d., cystic duct; d., duodenum; d. c. 



ductus choledochus; d. p., dorsal pancreas; h. d., hepatic duct; p. atic duct fof \VlT- 



duodenal papilla; p. d., pancreatic duct; St., stomach; v. p., ventral 



pancreas. sung], opens beside 



the common bile 

 The papilla is a hollow eleva- 



Blood vessel. 



duct at the base of the duodenal papilla. 

 tion of the mucosa, which 

 has been spread open in 

 Fig. 261, B. The larger 

 part of the pancreas grows 

 out separately, from the 

 dorsal wall of the duode- 

 num between the papilla 

 and the stomach. The 

 duct of this dorsal pancreas 

 is the accessory pancreatic 

 duct [of Santorini]. The 

 dorsal pancreas fuses with 

 the ventral so as to make a 

 single gland of uniform 

 structure, the former pro- 

 ducing its body and tail, 

 and the latter contributing 

 to the head. The two 



j , FIG. 262. AN ISLAND OP THE PANCREAS WITH THE 



QUCtS anastomose as Shown SURROUNDING ALVEOLI, PROM AN ADULT. X 400. 



in Fig. 261, B, and the out- 

 let of the ventral duct becomes predominant. The intestinal end of the 



