INTESTINAL DIGESTION 281 



saccharose, maltose, and lactose into dextrose and 

 levulose, two varieties of sugar which are assimilable. 

 These two sugars together form what is called invertin 

 sugar. 



The Part Played by the Bile in Digestion. The liver 

 plays a large part in digestion and nutrition of the 

 body. This important relation is due chiefly to the 

 secretion from the liver cells termed bile. 



Bile is continually secreted from the cells within 

 the lobules of the liver, and is collected by the tiny 

 biliary capillaries which join larger vessels to finally 

 end in the right and left hepatic ducts which leave 

 the transverse fissure of the liver, passing downward 

 after receiving the cystic duct from the gall-bladder, 

 and then pass downward and inward as the common 

 bile duct to open into the duodenum. The bile is 

 stored in the gall-bladder until needed, when it passes 

 through the above-mentioned passages to aid in the 

 intestinal digestion of the food. 



Bile obtained from the gall-bladder is of a thick, 

 viscid character, green or golden yellow in color, 

 specific gravity of 1.010 or 1.020. It is composed 

 chiefly of water, small quantities of sodium glycocho- 

 late, and sodium taurococholate, cholesterin, free fat, 

 sodium palmitate and stearate, lecithin, other organic 

 matters; sodium and potassium chlorides, sodium and 

 calcium phosphates, sodium carbonate. 



The flow of bile from the liver is continuous, influ- 

 enced by the process of digestion. It increases as 

 soon as food reaches the stomach, but its greatest 

 flow is not noted until about two hours later. After 

 this it decreases by degrees, but never entirely stops. 

 The bile is forced out of the gall-bladder by a con- 

 traction of its muscular walls. 



The Physiologic Functions of the Bile. (1) Aids in 

 digestion of fats, and by its contained bile salts 

 increases the action of the pancreatic enzymes in 

 splitting neutral fats, digesting starches and peptones; 



