ABSORPTION, STORAGE, AND ASSIMILATION 185 



2. In what different ways is the small intestine especially adapted 

 to the work of absorption ? 



3. What are the parts of a villus? What are the lacteals? Ac- 

 count for the name. 



4. What part is played by the capillaries and the lacteals in the 

 work of absorption ? How does their work differ? 



5. What changes, if any, take place in water, common salt, fat, 

 proteids, and carbohydrates during absorption ? 



6. What double purpose is served by the processes of digestion? 



7. Trace the passage of proteids, fats, and carbohydrates from the 

 small intestine into the general circulation. 



8. What is the necessity for storing nutrients in the body? Why 

 is it not also necessary to store up oxygen ? 



9. In what form and at what places is each of the principal 

 nutrients stored ? 



10. How is the rate of supply of food to the cells regulated? Why 

 is the body unable to regulate the supply of alcohol to the cells when 

 this substance is taken ? 



it. Explain Fig. 80, page 181. What becomes of the alcohol if 

 this is taken in any but very small quantities ? 



12. State the general purpose of enzymes in the body. Name the 

 enzymes found in each of the digestive fluids. What ones are found 

 in the tissues ? 



PRACTICAL WORK 



Illustrate the ordinary meaning of the term " absorption " by bringing 

 the end of a piece of crayon in contact with water, or a piece of blotting 

 paper in contact with ink, noting the passage of the liquid into the 

 crayon or the paper. Show how absorption from the food canal differs 

 from this kind of absorption. 



Show by a diagram similar to Fig. 77 the two routes by which the 

 foods pass from the alimentary canal into the blood stream. 



