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 the 

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



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 1M> : 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 



