THE BLOOD AND ITS CIRCULATION 7 1 



3. Fine tubes called capillaries receive the blood and 



give it out to the cells. 



4. Other tubes called veins carry the blood back to the* 



heart. 



5. The heart is a pump which keeps the blood in motion. 



6. Each stroke of the heart makes a wave in the arteries, 



which we can feel as the pulse. 



7. Cells eat the albumin and minerals which pass out of 



the capillaries, taking the food in by any part of 

 their bodies. 



8. The food which the cells do not use drains off in a set 



of tubes called lymphatics, which finally empty into 

 a vein near the heart. 



9. When a part needs more blood, the arteries become 



enlarged, and the heart pumps harder, so as to 

 carry more to it. 



10. Alcohol makes the arteries larger and causes the 



heart to beat quickly. 



11. Tobacco poisons the muscle of the heart. 



