110 



DIGESTION 



the pancreas to secrete its juice. The pancreatic juice 

 is a thin clear liquid containing several ferments. One 

 Of these ferments acts upon proteids and aids in finish- 

 ing the digestion of any part of them not completed 

 by the gastric juice of the stomach. Another finishes the 

 digestion of starch begun in the mouth by the saliva 

 and continued in the stomach until stopped by the acid 

 of the gastric juice. A third ferment acts upon fat, 

 which cannot be acted upon by either the saliva or the 

 gastric juice. 



Digestion of fat. The fat in animal tissues is in the 

 form of drops of oil which are stored up within the cells 

 of the connective tissue. The walls of these fat cells 



Connective tissue 



Nucleus of connective 



tissue cell 

 Protoplasm of cell 

 Fat globule within cell 



FIG. 74. Diagram showing storage of fat within connective tissue cells. 



are digested in the stomach by the gastric juice, so 

 that the fat is free when it enters the intestine. As a 

 result of the action of the pancreatic juice upon it, as- 

 sisted by the alkaline bile, the fat is so changed that 

 it can be readily absorbed through the walls of the in- 

 testine. The action of the pancreatic juice is not com- 



