PROBLEM 196 

 Fill out a diagram like the following : 



227 



Problem 194 : To study the method and place of absorption 

 in the human body. 



NOTE. — Absorption is the process by which digested food passes from 

 digestive canal through the walls of the blood vessels into the blood. 



the 



Materials. — Tripe, slides showing villi, charts. 



Observations. — Study the structure of tripe (stomach wall) 

 and the microscopic slide of a cross section of the small intestine. 

 Remember that the chief function of the small intestine is to get 

 food into the blood. 



Make a tube of paper having a diameter of 1 inch. Then try 

 to make a tube having the same diameter but having a folded wall. 

 Which takes more paper? Which would present more surface? 



Conclusion. — How is the structure of the wall of the intestine 

 fitted for absorption? 



Problem 195: To understand the structure of a villus. 



Method. — Study the figure of the villi on page 307, Civic Biol- 

 ogy; make sure you understand the use of each part. 



Conclusion. — 1. If blood goes into the villus, what change 

 in its composition might take place within it? 



2. How do fats get into the villi ? What becomes of the fats ? 



Problem 196 : How may foods be absorbed by the villi? 



Observations. — Suppose the villus is lined with a delicate skin- 

 like covering. How might liquid food pass through? Suppose 

 movements of other organs should press upon or squeeze the 



