1. CARDIOVASCULAR SYSTEM

2. Movement of Materials
The cardiovascular (AKA circulatory) system consists of the blood, blood vessels, and heart.
It carries needed substances to cells and carries waste products away.
Needed materials: oxygen, glucose, etc.
Waste products: carbon dioxide
Disease fighters: the cardiovascular system also transports disease-fighting cells.

3. The Heart’s Structure
The heart has 2 sides separated by tissue (left and right).
Each side has 2 chambers, an upper and a lower which are separated by valves.
The upper chamber is called an atrium, which receives blood that comes into the heart.
The lower chambers are called ventricles, which pump blood out of the heart.

4. How the Heart Works: 2 phases
In one phase, the heart relaxes and fills with blood.
In the other phase, the heart contracts and pumps the blood forward.

5. How the Heart Works: 2 phases
1) This squeezes blood out of the atria through the valves, and into the ventricles.
2) The ventricles contract and squeeze the blood into large blood vessels.

6. Regulation of Heartbeat
The pacemaker sends out signals that make the heart muscle contract, it is located in the right atrium.
The pacemaker receives messages about the body’s oxygen needs and adjusts the heart rate to match.

7. Blood Vessels
After leaving the heart, blood travels in blood vessels through the body.
There are 3 types of blood vessels:
Arteries: carry blood AWAY from the heart. “A” for “away.”
Capillaries: exchange substances between the blood and body cells.
Veins: carry blood back to the heart.

8. Loop 1: To the lungs and back…
Blood from the body flows into the right atrium and has little oxygen, but lots of carbon dioxide. ☹
The blood flows from the right atrium into the right ventricle.
Then the blood is pushed into the lungs where it can pick up oxygen and leave behind carbon dioxide.
Finally, the blood flows to the left side of the heart to go through the second loop.

9. Loop 2: To the body and back…
The left atrium fills with oxygen-rich blood from the lungs and then moves into the left ventricle.
Then the blood is pumped into the aorta, the largest artery, which sends blood to different blood vessels through your whole body.
The left ventricle contracts with the most force because it sends blood everywhere in your body.

10. Loop 2: To the body and back…
3) Blood flows through tiny capillaries in different parts of your body where oxygen moves out of the blood and into body cells.
4) The blood then picks up carbon dioxide and flows back to the right atrium of the heart through veins, completing loop 2.
THEN…everything starts all over again and LOOP 1 will begin!!!