5 th grade Life science 8/08 Mr. Harpers science mini lesson with audio Circulatory system and Respiratory system How blood keeps you alive
/ Every living thing is made up of tiny living parts called cells. Muscle cells Bone cells Skin cells Blood cells Skin cells Brain cells
/ / Your body is made of many billions of cells. One cell is too small to see without a microscope.
Every cell in your body needs a steady supply of oxygen or it will die. Cells must also get rid of carbon dioxide (CO 2 ) or they will die.
/ / 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 CO 2 away.
Blood in the capillary cell Bloodflow in capillary cell Oxygen molecules = cell Carbon dioxide (CO2) = \ capillary The walls of these capillaries are so thin that oxygen and CO 2 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.
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 part of your body every second you are alive.
There are 4 chambers or sections in the human heart. Right atrium Left atrium Right ventricle
Big tubes called arteries and veins carry blood in and out of the heart.
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.
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.
Most drawings of the circulatory system show arteries in red and veins in blue.
Arteries leading away from the heart get smaller and smaller as they branch out through every part of the body.
Arteries get really small until they branch into the smallest vessels called capillaries.
Capillary walls are so thin that oxygen and carbon dioxide (CO 2 ) can pass right through them in and out of the bodys cells. cell
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 CO 2 can only pass between blood and cells from the tiny capillaries.
There are millions of red blood cells in every drop of blood.
Every drop of blood has to go through a capillary to get back to the heart. Oxygen rich blood coming from the heart artery vein Oxygen poor blood going back to the heart Capillaries connecting arteries to veins Oxygen and CO 2 can only pass from blood to the cells from the tiny capillaries.
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
The blood returning to the heart in the veins is full of poisonous carbon dioxide (CO 2 ). Next, the heart pumps this blood to the lungs where CO 2 is exchanged for fresh oxygen. To the lungs
Lungs are the main organs in the… respiratory system
The respiratory system brings oxygen into your blood and gets CO 2 out.
Lungs When you breath in, your lungs pull air containing oxygen into your body. oxygen
Lungs When you breath out, your lungs push air containing CO 2 (carbon dioxide) out of your body. CO 2
Air travels from the nose and mouth to the lungs through a tube called the trachea or windpipe. (TRAY kee uh)
The trachea branches into the bronchi to go into each lung. Bronchi (rhymes with donkey) is the plural for bronchus 1 bronchus 2 bronchi
The bronchi branch smaller and smaller as they carry air to millions of tiny air sacs in the lungs.
The blood coming to the lungs from the heart is full of CO 2. The blood vessels branch smaller and smaller into capillaries that surround the air sacs. Air sac You have millions of air sacs in your lungs. They are much smaller than shown here. lung heart
Air sacs are so thin that oxygen and CO 2 can pass right through them to go in and out of the capillaries.
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.
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 Oxygen rich blood going out to the upper body
Oxygen rich blood from lungs Oxygen rich blood going out to the lower body 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.
Now, lets review the important information to find out how much you remembered.
Lets Review: What is the most important organ in the circulatory system?
The heart is the most important organ in the circulatory system.
Lets Review: How many chambers does the heart have?
Lets Review: 1 2 A human heart has 4 chambers. 3 4
Lets Review: What are the vessels that carry oxygen-rich blood from the heart out to every cell in your body?
Lets Review: Arteries are the vessels that carry oxygen-rich blood from the heart out to every cell your body.
Lets Review: What are the vessels that carry oxygen-poor blood from the cells back to the heart?
Lets Review: Veins are the vessels that carry oxygen-poor blood from the cells back to the heart.
Lets Review: What are the tiny vessels that connect arteries to veins?
Lets Review: are the tiny vessels that connect arteries to veins. Capillaries
Lets Review: What important activity happens only around the capillaries?
Lets Review: Your bodys cells get oxygen and get rid of CO 2 only from the capillaries. This is called gas exchange.
Lets Review: Where does blood go after it returns to the heart from the cells?
Lets Review: The heart immediately pumps the CO 2 filled blood from the cells to the lungs.
Lets Review: What happens to blood when it goes through the lungs?
The blood exchanges gases (gets rid of CO 2 and fills up with oxygen) when it goes through the lungs,
Lets Review: What is in blood that acts like tiny buckets to carry oxygen and CO 2 ?
Red blood cells act like little buckets that carry oxygen and CO2 in the blood.
/ Circulatory system Respiratory system Heart Blood To learn more about the body systems that keep you alive, check out these Brainpop cartoons: