280 DIGESTION, CIRCULATION, AND ABSORPTION 



d. Summary of Adaptions for Absorption 



Fill in the following table : 



Questions 



1. What are the uses of the lacteals ? 



2. What nutrients are digested and absorbed in only one 

 organ ? 



3. Why must food be absorbed into the blood ? 



4. What is necessary before most foods can be absorbed ? 



5. What is the portal system ? The thoracic duct? 



6. Which of the following pass into the lacteals, and which 

 into the capillaries of the portal vein sugar, peptones, 

 emulsified fats? 



7. Name the organs of absorption in the small intestine. 



8. Water and salt need no digestion. Why? Where are 

 they absorbed? 



9. Through what large tube is the fat carried in passing 

 from the lacteals to the veins? 



10. Where do the capillaries that take part in absorption 

 empty? 



11. What provision is made for storing sugar so that it will 

 not pass suddenly to the cells after a meal, but be given to them 

 gradually? Note. Food is assimilated, or changed into living 

 matter (protoplasm), in the cells. 



12. What changes take place in the composition of the 

 blood in the lining of the stomach? In the small intestine? 



