2 go 



HISTOLOGY 



The left lobe of the ventral pancreas sometimes grows around the left side of the 

 intestine and joins the dorsal pancreas, so that the intestine is encircled by pancreatic 

 tissue (annular pancreas); sometimes it grows out beneath the gall bladder where it 

 ends in a cystic enlargement, as has been observed in adult cats (cf. Amer. Journ. Anat., 

 191 2, vol. 1 2, pp. 380-400). Usually the left lobe is scarcely indicated. As a rather fre- 

 quent abnormality, accessory pancreases of small size, but sometimes of very typical 



D. ch. 



p. d. 



L. d. 



L.s. 



Int. 



P d. 



L. d. 



Pr. v. 



D. ch. 



L. s. 



Int. 



A B 



FIG 286. MODELS OF THE VENTRAL PANCREAS IN PIG EMBRYOS. X 120. 



A, 5.1 mm., B, 6.0 mm. D. ch., ductus choledochus; Int., intestine; L. d., right lobe, and L. s., left lobe of 

 the ventral pancreas; P. d., dorsal pancreas; Pr. v., ventral process of the dorsal pancreas. 



structure, are found along the intestine, or even in the wall of the stomach, especially 

 at the constriction between its cardiac and pyloric portions. Such glands may or may 

 not extend through the tunica muscularis. 



After the dorsal and ventral pancreases have come in contact, they are 

 related to one another as shown in Fig. 287, A. The dorsal pancreas is 



much larger than the 

 ventral pancreas, and 

 it grows across the 

 body toward the left 

 until it reaches the 

 spleen. Thus it gives 

 rise to the body and 

 tail of the pancreas 

 of the adult; and it 

 forms also the ventral 

 part of the head of 



. p. d., Accessory pancreatic duct; c. d., cystic duct: d., duodenum; d. c., .-> i j i i /-ii 



ductus choledochus; d. p., dorsal pancreas; h. d., hepatic duct; p., duo- trie gland. WlllCn nils 

 denal papilla; p. d., pancreatic duct; St., stomach; v. p., ventral pan- . 



crea - the concavity in the 



duodenal loop. In 



the adult its duct opens into the duodenum 1-3 cm. above the orifice of the 

 common bile duct, but it has been tapped by an anastomosis with the ventral 

 pancreas. Its outlet persists as the accessory pancreatic duct, discovered by 

 Santorini (1775). It is shown in the dissection, Fig. 287, B, but a large 



FIG. 287. A, DIAGRAM OF THE PANCREAS FROM A IS-MM. HUMAN EM- 

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

 ADULT. (After Schinner.) 



