316 DISSECTION OP THE BABBIT 



A. External Characters of the Digestive System. 



1 . The stomach. 



Expose the stomach fully, by turning the liver forwa/rds, 

 and the intestine over to the animal's left. 



The stomach is much dilated at its left or cardiac 

 end ; narrower towards the right or pyloric end ; 

 and markedly curved, the concavity being directed 

 forwards. Near the left end of its anterior border is 

 the cardia, or opening of the oesophagus ; and from 

 the thick-walled pyloric end a small aperture, the 

 pylorus, leads to the duodenum. 



2. The duodenum, or first portion of the intestine, runs 



from the pylorus along the right side of the ab- 

 dominal cavity almost to its hinder end : it then 

 turns back on itself, forming a U -shaped loop. In 

 the mesentery connecting the two limbs of the loop 

 are the large duodenal vessels. 



3. The pancreas. 



Turn the duodenal loop over to the left side without 

 injuring the mesentery, and spread it out over the other 

 viscera. 



The pancreas is a diffuse fat-like gland of a 

 pinkish colour, scattered in the mesentery of the 

 duodenal loop. It lies mainly around the large 

 vessels of the loop, and is more compact at its 

 anterior end. 



The pancreatic duct commences in front, and 

 runs backwards through the gland, receiving smaller 

 ducts from its several lobes ; it opens into the inner 

 side of the distal limb of the duodenal loop, about 

 three inches beyond the bend. 



Open the duodenum, opposite to the entrance of the pan- 

 creatic duct; wash out the contents ; note the aperture of the 

 duct, and insert a bristle into it. 



4. The liver is a large solid organ, thick in the middle and 



thinning towards the edges. Its anterior surface is 



