192 Physiology. 



Summary. i . The cells lining the digestive tube take up the 

 digested food, now in liquid form, and pass it into the lymph. 



2. There is some absorption, from the stomach, of sugar and 

 peptone. Most of the absorption is from the small intestine. 



3. The hair-like villuses greatly increase the absorbing surface. 



4. A villus has four parts, the outer layer of cells, plain muscle 

 fibers running lengthwise, blood capillaries, and lacteals. 



5. The outer cells of the villus take up the liquefied food. 



6. Sugar and proteids enter the blood capillaries; fats enter 

 the lacteal capillaries. 



7. The muscles of the villus pump the liquids along and aid 

 absorption. 



8. The lacteals are part of the lymph system of the body. They 

 absorb and carry fats. 



9. The veins from the stomach and intestine join to form the por- 

 tal vein which enters the liver. Here it breaks up into capillaries. 



10. The liver has two supplies of blood, from the portal vein and 

 the hepatic artery. It is drained by one vein, the hepatic vein. 



1 1 . The liver makes bile and glycogen. 



12. Sugars and proteids go through the liver; fats pass around the 

 liver through the main lymph vein, or thoracic vein. 



13. There are over two gallons of liquids absorbed daily. 



Questions. i. Why is it best to begin a hearty meal with soup ? 



2. Why should the liver receive so much blood ? 



3. What is the meaning of " biliousness " ? 



4. What is the advantage of a " fruit diet " ? 



5. Why does active exercise tend to keep the bowels open ? 



