Circulatory system

5th grade Life science8/08Mr. Harpers science mini lesson with audio

Circulatory systemandRespiratory systemHow blood keeps you alive

1/Every living thing is made up of tiny living parts called cells.

Muscle cells

Bone cells

Skin cellsBlood cellsSkin cells

Brain cells

//

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

3 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.

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

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

Blood in the capillarycellBloodflow in capillarycellcellcellOxygen molecules =cellcellCarbon dioxide (CO2) =\

capillaryThe walls of these capillaries are so thin that oxygen and CO2 can pass easily in and out of the cells.

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

8 The heart is the main organ in the circulatory system. Its a muscle that never gets tired as it continues to

pump blood to every partof your bodyevery second you are alive.

9

There are 4 chambers or sections in the human heart.Right atriumLeft atriumRight ventricleRight ventricle

10Big tubes called arteries and veins carry blood in and out of the heart.

11 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.

12

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.

13

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

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

15

Arteries get really small until they branch into the smallest vessels called capillaries. 16 Capillary walls are so thin that oxygen and carbon dioxide (CO2) can pass right through them in and out of the bodys cells.

cellcellcell17 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.

18There are millions of red blood cells in every drop of blood.

19Every drop of blood has to go through a capillary to get back to the heart.

Oxygen rich blood coming from the heartarteryveinOxygen poor blood going back to the heartCapillaries connecting arteries to veins Oxygen and CO2 can only pass from blood to the cells from the tiny capillaries.

20 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 heartveins

21

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

22Lungs are the main organs in therespiratory system

23respiratory system

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

25

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

26

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

27

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

28 The trachea branches into the bronchi to go into each lung.Bronchi (rhymes with donkey) is the plural for bronchus1 bronchus2 bronchi

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

30

The blood coming to the lungs from the heart is full of CO2. The blood vessels branch smaller and smaller into capillaries that surround the air sacs. Air sacYou have millions of air sacs in your lungs. They are much smaller than shown here.

lungheart31 Air sacs are so thin that oxygen and CO2 can pass right through them to go in and out of the capillaries.

32 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.

33

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 lungsOxygen rich blood going out to the lower bodyOxygen rich blood going out to the upper body

34Oxygen rich blood from lungsOxygen rich blood going out to the lower bodyOxygen 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.35 Now, lets review the important information to find out how much you remembered.

36Lets Review:What is the most important organ in the circulatory system?

37The heart is the most important organ in the circulatory system.

38Lets Review:How many chambers does the heart have?

39Lets Review:

12A human heart has 4 chambers.34

40Lets Review:What are the vessels that carry oxygen-rich blood from the heart out to every cell in your body?

41Lets Review:

Arteries are the vessels that carry oxygen-rich blood from the heart out to every cell your body.

42Lets Review:What are the vessels that carry oxygen-poor blood from the cells back to the heart?

43

Lets Review:Veins are the vessels that carry oxygen-poor blood from the cells back to the heart.

44Lets Review:What are the tiny vessels that connect arteries to veins?

45Lets Review: are the tiny vessels that connect arteries to veins.

Capillaries

46Lets Review:What important activity happens only around the capillaries?

47Lets Review:Your bodys cells get oxygen and get rid of CO2 only from the capillaries. This is called gas exchange.

48Lets Review:Where does blood go after it returns to the heart from the cells?

49Lets Review:The heart immediately pumps the CO2 filled blood from the cells to the lungs.

50Lets Review:What happens to blood when it goes through the lungs?

51The blood exchanges gases (gets rid of CO2 and fills up with oxygen) when it goes through the lungs,

52Lets Review:What is in blood that acts like tiny buckets to carry oxygen and CO2?

53Red blood cells act like little buckets that carry oxygen and CO2 in the blood.

54/Circulatory systemRespiratory systemHeartBlood

To learn more about the body systems that keep you alive, check out these Brainpop cartoons: