Download Bill Nye Video : The Heart

SCIENCE 8
Bill Nye Video : The Heart - ANSWERS (25 minutes)
1. The heart is a muscle about the size of your fist.
2. Your heart is a pump that pushes blood all over your body.
3. Your blood carries fuel - energy from your food and oxygen, and carries wastes away too.
4. Heart sends blood in two directions.
5. Blue blood has very little oxygen.
6. It comes from your body and is pumped to your lungs to get oxygen.
7. Red blood is oxygen-rich. It gets pushed from your lungs back to your heart and then gets
pumped to all parts of your body.
8. The heart is the pump for your circulatory system.
9. Your heart has two sides, and each side has two chambers, so all together there are four
chambers.
10. Your heart has valves like gates between the top and bottom chambers.
11. Valves keep the blood flowing in one direction.
12. A normal heart beats 60 to 100 beats per minute at rest.
13. Your heart speeds up during intense physical exercise because your muscles need more
oxygen.
14. Exercise also strengthens your heart which is a muscle.
15. Electricity makes your muscles move.
16. Electricity makes your heart contract.
17. The sinoatrial nerves are your heart’s natural pacemaker.
18. The muscles in your arm are striated muscles that contract to make your skeleton move.
19. The muscles in your stomach are smooth muscles that contract slowly and can stay
contracted for a long time.
20. Heart muscle is like both smooth and striated muscle. It doesn’t get tired and it’s very strong.
21. Smooth and skeletal muscles contract only when the nervous system tells them to.
22. Only the heart muscle cells contract on their own.
23. Every time your heart pumps, the blood leaves from the left ventricle and goes up to your
body system. Then it comes back to your right atrium. Then it goes down to your right
ventricle then up to your lungs and your left atrium. Then down again to your left ventricle.
24. Fat can cause blood clots to block the flow of blood to the heart, so it does not get enough
oxygen, causing a heart attack.
25. Too much fat can be bad because it clogs your arteries and blood vessels.