1. Circulatory system and Respiratory system
Mr. Harper’s science mini lesson with audio
5th grade Life science
8/08
Circulatory system and Respiratory system
How blood keeps you alive

2. Every living thing is made up of tiny living parts called cells./
Skin cells
Muscle cells
Skin cells
Bone cells
Blood cells
Brain cells

3. Your body is made of many billions of cells
Your body is made of many billions of cells. One cell is too small to see without a microscope. / /

4. Every cell in your body needs a steady supply of oxygen or it will die.
Cells must also get rid of carbon dioxide (CO2) or they will die.

5. Every cell in your body lives right next to a tiny blood vessel (tube) called a capillary./ /

6. The blood in our circulatory system brings oxygen to every cell through the capillaries and carries CO2 away. / /

7. The walls of these capillaries are so thin that oxygen and CO2 can pass easily in and out of the cells.
Oxygen molecules =
Carbon dioxide (CO2) =
capillary
Bloodflow in capillary
Blood in the capillary \
cell
cell
cell
cell
cell
cell

8. Your heart, blood, and the tubes that carry the blood all work together as a system, your circulatory system.

9. The heart is the main organ in the circulatory system
The heart is the main organ in the circulatory system. It’s a muscle that never gets tired as it continues to
pump blood
to every part
of your body
every second
you are alive.

10. There are 4 chambers or sections in the human heart.
Left atrium
Right atrium
Right ventricle
Right ventricle

11. Big tubes called arteries and veins carry blood in and out of the heart.

12. Arteries carry blood from the heart out to all parts of the body
Arteries carry blood from the heart out to all parts of the body. This blood is rich with oxygen which gives it a bright red color.
In drawings like this, arteries are colored red.

13. Veins carry blood back to the heart from all parts of the body
Veins carry blood back to the heart from all parts of the body. This blood is oxygen-poor and is full of carbon dioxide. This gives the blood a purple-brown color In drawings veins are colored blue.

14. Most drawings of the circulatory system show arteries in red and veins in blue.

15. Arteries leading away from the heart get smaller and smaller as they branch out through every part of the body.

16. Arteries get really small until they branch into the smallest vessels called capillaries.

17. Capillary walls are so thin that oxygen and carbon dioxide (CO2) can pass right through them in and out of the body’s cells.
cell
cell
cell

18. Red blood cells in the blood act like little buckets that carry oxygen to and carbon dioxide away from every cell in your body.
Oxygen and CO2 can only pass between blood and cells from the tiny capillaries.

19. There are millions of red blood cells in every drop of blood.

20. Every drop of blood has to go through a capillary to get back to the heart.
Oxygen and CO2 can only pass from blood to the cells from the tiny capillaries.
artery
Oxygen rich blood coming from the heart
Capillaries connecting arteries to veins
Oxygen poor blood going back to the heart
vein

21. At the end of the capillary, blood goes into a vein
At the end of the capillary, blood goes into a vein. The veins leading back to the heart get bigger and bigger as they branch together.
Used blood going back to the heart
veins

22. The blood returning to the heart in the veins is full of poisonous carbon dioxide (CO2).
To the lungs
Next, the heart pumps this blood to the lungs where CO2 is exchanged for fresh oxygen.

23. Lungs are the main organs in the…
respiratory system

24. respiratory system

25. The respiratory system brings oxygen into your blood and gets CO2 out.

26. When you breath in, your lungs pull air containing oxygen into your body.

27. When you breath out, your lungs push air containing CO2 (carbon dioxide) out of your body.

28. Air travels from the nose and mouth to the lungs through a tube called the trachea or windpipe.
(TRAY kee uh)

29. The trachea branches into the bronchi to go into each lung.
Bronchi (rhymes with donkey) is the plural for bronchus
1 bronchus
2 bronchi

30. The bronchi branch smaller and smaller as they carry air to millions of tiny air sacs in the lungs.

31. lung
The blood coming to the lungs from the heart is full of CO The blood vessels branch smaller and smaller into capillaries that surround the air sacs.
heart
Air sac
You have millions of air sacs in your lungs. They are much smaller than shown here.

32. Air sacs are so thin that oxygen and CO2 can pass right through them to go in and out of the capillaries.

33. The red blood cells get rid of the CO2 they are carrying and fill up with fresh oxygen as they pass through the capillaries around the air sacs.

34. Oxygen rich blood going out to the upper body
When the blood leaves the lungs, it is full of oxygen and bright red again. The blood goes back to the heart to be pumped out and take oxygen to all parts of the body.
Oxygen rich blood from lungs
Oxygen rich blood going out to the lower body

35. Oxygen rich blood going out to the upper body
For as long as you live, your blood will continue to “circle” around your circulatory system and through your lungs to bring your cells what they need to live.
Oxygen rich blood from lungs
Oxygen rich blood going out to the lower body

36. Now, let’s review the important information to find out how much you remembered.

37. What is the most important organ in the circulatory system?
Let’s Review:
What is the most important organ in the circulatory system?

38. The heart is the most important organ in the circulatory system.

39. How many chambers does the heart have?
Let’s Review:
How many chambers does the heart have?

40. A human heart has 4 chambers.
Let’s Review:
A human heart has chambers. 3 1 4 2

41. Let’s Review:
What are the vessels that carry oxygen-rich blood from the heart out to every cell in your body?

42. Let’s Review:
Arteries are the vessels that carry oxygen-rich blood from the heart out to every cell your body.

43. Let’s Review:
What are the vessels that carry oxygen-poor blood from the cells back to the heart?

44. Let’s Review:
Veins are the vessels that carry oxygen-poor blood from the cells back to the heart.

45. What are the tiny vessels that connect arteries to veins?
Let’s Review:
What are the tiny vessels that connect arteries to veins?

46. Capillaries are the tiny vessels that connect arteries to veins.
Let’s Review:
Capillaries
are the tiny vessels that connect arteries to veins.

47. What important activity happens only around the capillaries?
Let’s Review:
What important activity happens only around the capillaries?

48. Let’s Review:
Your body’s cells get oxygen and get rid of CO2 only from the capillaries. This is called gas exchange.

49. Where does blood go after it returns to the heart from the cells?
Let’s Review:
Where does blood go after it returns to the heart from the cells?

50. Let’s Review:
The heart immediately pumps the CO2 filled blood from the cells to the lungs.

51. What happens to blood when it goes through the lungs?
Let’s Review:
What happens to blood when it goes through the lungs?

52. The blood exchanges gases (gets rid of CO2 and fills up with oxygen) when it goes through the lungs,

53. What is in blood that acts like tiny buckets to carry oxygen and CO2?
Let’s Review:
What is in blood that acts like tiny buckets to carry oxygen and CO2?

54. Red blood cells act like little buckets that carry oxygen and CO2 in the blood.

55. Circulatory system Respiratory system Heart Blood
To learn more about the body systems that keep you alive, check out these Brainpop cartoons: /
Circulatory system
Respiratory system
Heart
Blood