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BACK IN CIRCULATION
PAGES 126-129
1. Explain why the circulatory system is called a closed system. There is
no entry or exit.
2. How does our body offer the heart protection? The heart is nestled
in the chest cavity, cushioned by soft, spongy lungs and surrounded by
a sac called the pericardium.
3. What are vessels that carry blood FROM the heart called (3 answers~
large to small vessels) arteries, arterioles, capillaries
4. How long does it take one blood cell to enter the heart, move through
the body and return to the heart? 60 seconds
5. How does the heart know when to beat? Heartbeats are caused by
electrical impulses from a pocket of specialized cells called the
pacemaker.
6. Why is the heart considered to be composed of two pumps? One side
moves blood from the heart to the lungs. The other side moves blood
from the heart to the rest of the body.
7. What are the upper chambers of the heart called? atrium
8. What are the lower chamber of the heart called? ventricles
9. What is circulation called between the heart and lungs? pulmonary
10. What is circulation called between the heart and the rest of the
body? systemic
Not found in reading selection…..
11. Could the circulatory system work without the respiratory system?
Explain your answer.
12. How does the circulatory system work with the digestive system?
13. How does the digestive system work with the respiratory system?