APPLIED PHYSIOLOGY 



3. The exchange in the two sets of capillaries balances. 



4. Within the living cells the oxygen unites with the 



albumin, fat, and sugar, producing carbonic acid 

 gas, water, and urea. 



5. About twenty-five ounces of oxygen are used daily in 



oxidizing the body. 



6. When not enough oxygen is present within the body, 



there is a shortness of breath. 



7. Alcohol often causes distension and thickening of the 



capillaries and of the walls of the air sacs, so that 

 oxygen passes through them less readily. 



8. The alcohol of three or four strong drinks of liquor 



uses as much oxygen as would supply the whole 

 body for two hours. 



9. As a result of taking oxygen from the cells of the 



body, the cells act in an uncertain manner, which is 

 called intoxication. 



10. Tobacco smoke irritates the air passages. It contains 



nicotine, which can enter and poison the body. 



11. All kinds of animals and plants breathe in oxygen 



and give off carbonic acid gas. 



DEMONSTRATIONS 



89. With a glass tube, blow air through some limewater, and notice 

 that it grows milky, showing the presence of carbonic acid gas. Breathe 

 upon a cold glass and notice that moisture collects from the breath. 

 Call attention to the fact that bad odors in the breath are due to de- 

 cayed teeth, a coated tongue, or foul stomach, or possibly to a dirty nose. 



90. The change in color from venous to arterial blood can be illus- 

 trated by cutting into a thick slice of beef. At first the cut surface is 

 dark and purplish, and of the color of venous blood. But in a few sec- 

 onds the blood in the meat absorbs oxygen from the air and becomes 

 bright red in color like arterial blood. 



91. With two needles tease apart a bit of gill from a shellfish and 

 examine it with the microscope for the waving cilia. 



