1. Circulatory System

2. The Circulatory System The circulatory, or cardiovascular, system is made up of the heart, blood vessels, and blood. In one day, human hearts beat about 100,000 times and pump around 1,500 gallons of blood! Whew! I’m tired!

3. What does it do for us? Our circulatory system… Delivers necessary materials (like oxygen and sugar) to the entire body in the blood, Removes waste products from cells, and Helps fight disease by transporting immune cells in the blood.

4. How does it move stuff? The circulatory system is like a system of roads that links your entire body The “roads” are blood vessels – some are like superhighways, and others are like small one- lane paths. Your blood travels on these roads like a “mail man” – it both delivers and picks up important materials.

5. How does it move stuff? Your blood travels in two main loops: 1.From the heart to the lungs and back, and 2.From the heart to the body and back.

6. How does it move stuff? Basically, your blood follows this cycle: Blood enters the right side of the heart and is pumped out again. Blood enters the left side of the heart and is pumped out again. Blood gets rid of carbon dioxide and picks up oxygen. Blood delivers oxygen to body and picks up waste (like carbon dioxide).

7. Oxygen- poor blood from the body enters the right side of the heart and is pumped out to the lungs. Oxygen- rich blood from the lungs enters the left side of the heart and is pumped out to the body.

8. How does it move stuff? Your heart is the pump that sends the blood through the system. The heart is a hollow, muscular organ. Inside the heart, there are four main chambers: two atria (right and left) and two ventricles (right and left). RIGHT ATRIUM RIGHT VENTRICLE LEFT ATRIUM LEFT VENTRICLE

9. What’s inside your heart? The right and left sides of the heart are separated by a wall of tissue called the septum. SEPTUM

10. What’s inside your heart? The atria and ventricles are separated by valves, which prevent blood from flowing in the wrong direction. VALVE The atria receive the incoming blood, and the ventricles pump it back out, either to the lungs or to the body.

11. From Body Right Atrium Right Ventricle To Lungs From Lung Left Atrium Left Ventricle To Body So, the detailed path of blood in your body would look like this: Body Lung

12. What’s inside your heart? This is a real sheep heart. Look at how thick the walls of the ventricles are. Why is this? The ventricles are in charge of pumping the blood out to the entire body. They need to be thick and strong to have enough force!

13. What carries the blood? BLOOD VESSELS are the hollow tubes that carry your blood around your body. There are 3 TYPES: –ARTERIES –CAPILLARIES –VEINS

14. What carries the blood? Arteries carry blood away from the heart. They are very thick, and have strong, muscular walls to withstand the pressure created by the heart.

15. What carries the blood? Capillaries are tiny vessels that run through your body tissue. They are very thin to allow oxygen and waste to pass between the vessels and your cells.

16. What carries the blood? Veins carry blood back to the heart. They have thinner walls than the arteries because there is not as much pressure from the heart.

17. What is your blood? Blood is not one single substance – it is a mix of liquid and cells. The liquid part of blood is called plasma. It is mostly water. The rest of the blood is made of three types of cells.

18. What is your blood? Red Blood Cells carry oxygen. White blood cells fight disease. Platelets form blood clots to stop you from bleeding too much.