DIGESTION, CIRCULATION, AND ABSORPTION 289 



10. The systemic circulation. 



11. Lymph and its functions. 



12. What is a tourniquet ? 



The portal circulation. 



References 



Hunter, Essentials of Biology. Chap. XXVI. 

 Hunter, Elements of Biology. Chap. XXX. 



PROBLEM L 



Some changes in the composition of the blood. 

 a. Absorption 



Observations. 1. What is ready to be added to the blood 

 from the stomach? Small intestine ? 



2. What per cent of food that reaches the blood is absorbed 

 by the villi of the small 



intestine ? 



3. What nutrient ab- 

 sorbed by the lacteals ? 



4. What is the por- 

 tal system ? 



Conclusion. Sum 

 up all the changes in 

 the composition of the 

 blood, due to absorp- 

 tion. 



b. 



A Special Use of 

 Plasma 



Observations. 1. 



What part of the blood 

 is able to pass through 

 the walls of the capil- 

 laries ? Note that it is 

 now called lymph. 



2. What is the reason for the process ? 

 SHARPE'S LAB. MAN. 19 



FIG. 70. Diagram of the capillaries uniting an 

 artery and a vein. The plasma is passing 

 through the walls of the capillaries to nourish 

 the hody cells, after which some of it enters 

 the mouths of the lymph vessels and the rest 

 passes back to the capillaries. 



