PROBLEM 106 

 Fill out a diagram like tlie folhjwing : 



2'n 



Probletn 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 trijx^ (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 Ijut lia\ ing 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 Wr>: To understand the structure of a villus. 



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

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



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

 in its composition might take place witliin it? 



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



Problem lf)(i : IIoiv uuty foods be absorbed by the rilli? 



Observations. — Suppose* the villus is lined with a dclicMlc -kin- 

 like covering. How might li(|ui(l food pass through? Suppose 

 movements of other organs should i)ress upon or s(j:ieezc the 



