XII 



i)i;rsTION 



'43 



is (he case, for instance, with the white of egg) or still remain 

 in solution, and are in part (hanged into peptone. 



The gastric juice acts only on the proteids ; it has no 

 action on the carbohydrates or on the fats. It, however, 

 assists in the digestion of these food -stuffs, because by dis- 

 solving the proteids of the tissues taken as food in which they 

 lie it breaks up the material, and so sets the other food-stuffs 

 free. The warmth of the stomach also, to some extent, melts 

 the fats. 



After a variable time, which may be one to three or four 



vcr 



MS. 



KM.. 64. The pancreas and spleen. 



-T//, spleen with splenic artery A/..-), coming from the aorta, Af. Below the splenic 

 artery is the splenic vein K"'"v; t" tin- portal vein I'. I'.; /'./>, pancreatic duct 

 ili-.sc. ted out in the substance of the pancreas opening with HI), the bile duct, 

 at x into the duodenum Din. I 'L'f, inferior vena cava ; />, diaphragm ; y, 

 intestinal vessels. 



hours, the contents of the stomach, which are called chyme, 

 are allowed to pass on into the duodenum. This is caused by 

 the ring-like muscular tissue of the wall of the pylorus relaxing 

 at intervals and so allowing some of the chyme to be sent on 

 by the contractions of the walls of the stomach. 



In the duodenum the chyme is acted on by two juices, the 

 pancreatic juice and the bile. 



Structure of the Pancreas. The pancreas, which 

 secretes the pancreatic juice, lies, ;is we have seen, in the bend 



