THE DIGESTION 



219 



as to show the Bile 

 Duct (a) and the 

 Pancreatic Duct (b) 

 opening by a Com- 

 mon Orifice. 



duct. Where does this duct empty ? The fats are thus 



taken into the blood stream. 



390. The Intestinal Glands. Besides the two large 



glands, the pancreas and liver, there are 



a great number of very small glands (Fig. 



172) which furnish a digestive fluid to 



the intestine. The intestinal glands are 



scattered throughout the lining membrane, 



and their secretion is called the intes- 

 tinal juice. It is difficult to isolate and 



to study because of the minuteness of the 



glands, and although their functions are 



not fully known, it has been proven that 



their secretion can digest cane sugar and 



maltose and change them into grape sugar, 



or glucose. If cane sugar is injected into 



the arteries, it is excreted from the body unchanged. 



This proves that the body is incapable of assimilating 



cane sugar until it is digested. 

 391- Forms of Sugar and 

 Starch. Cane sugar is found 

 in sugar cane, sorghum, and 

 sugar beets. Milk sugar is 

 found in milk. Malt sugar 

 is produced by the action of 

 saliva upon starch. Grape 

 sugar (and fruit sugar, which 

 intestine is nearly the same) is the 

 sweet element in fruits and 

 honey. 



Malt sugar, while passing 

 through the mucous mem- 

 brane of the intestine, is con- 



FIG. 175. The Digestive System. verted into grape sugar, and 



in this form it is absorbed into the blood. It may be 



Pancreas 



-V Small 



Vermiform . 

 Appendix 



