THE NOSTRILS AND PHARYNX 383 



2. Is the heart a suction pump or a force pump? Why has the left 

 ventricle stronger muscles than the other heart chambers? 



3. Why does the doctor "take your pulse" when you are ill? Why 

 does he take your temperature? 



4. What is meant by the " transfusion " of blood? 



5. Why is the blood in the veins l ' blue blood ' ' ? How, in an accident, 

 can you tell that you have cut an artery rather than a vein? Which 

 would be the more serious, and why? On which side of a wound ought 

 an artery to be compressed, so as to stop bleeding, on the side toward 

 the heart or on the side away from the heart? How, in the case of a 

 cut vein? 



6. Draw a sketch showing the cells of a capillary wall (a single layer, 

 end to end), and show how an ameba-like cell, such as a white corpuscle, 

 might get out. 



7. What is the special duty of red corpuscles? Of the white ones? 

 What body fluid forms the "matter" of a blister? 



8. If you were on a high mountain top, would there be as much 

 oxygen in every breath as at sea level? How do you think the body can 

 increase the oxidation of the blood at high altitudes? 



9. When does the heart have more work to do, when we stand, or 

 when we he down? Why? 



10. Do you think continued and violent physical exercise would 

 have any effect on the size of the heart? Why? 



11. When a boy or girl grows very, rapidly, how is the heart's work 

 affected? Ought violent exercise to be indulged in at this time? 



12. Why are you "out of breath" after running? 



13. How does a very dry atmosphere affect the organs of respira- 

 tion? (Cf. 249). 



14. Give the course of air in going from the nostrils into the lungs. 

 Give the course of the oxygen from the lungs, through the body cir- 

 culation, and back again to the lungs. 



387. The Nostrils and Pharynx. The air that enters 

 the lungs goes through a passage consisting of several 

 parts; these are: the nasal passages, or nostrils, the 

 pharynx, or throat, the larynx, the trachea, or windpipe, 



