1. Unit 2 Structures of Living Things
Lesson 2
How do the circulatory and respiratory systems work together?

2. Circulatory System
The circulatory system is a group of organs that transports needed materials throughout the body.

3. Respiratory System
The respiratory system is a group of organs and tissues that exchanges oxygen and carbon dioxide between your body and the environment.
(0:26)

4. The Heart
The heart is one of the most important organs in the body. It is the pumping organ which is made up of a double pump with four chambers. It normally beats at a steady rate.

5. Before your heart beats, two of the chambers fill with blood.
Then, the heart contracts and squeezes blood into large tubes, or blood vessels.

6. The path of blood
Blood from the body returns to the heart and then pumps it to the lungs
Carbon dioxide is then exchanged from for oxygen.
(1:07)

7. The four steps of blood flow through the heart:
Pulmonary arteries carry blood away from the heart to the lungs.
Oxygen rich blood from the lungs returns to the heart.
The heart pumps blood to all parts of the body through arteries.
Veins carry blood from the body back to the heart.

8. The Circulatory system
The circulatory system transports blood loaded with oxygen and nutrients to each cell of the body.
It takes away wastes from the cell
It is made up of the heart, blood vessels, and blood.

9. Blood The liquid part of blood is called plasma and is mostly water.
It carries nutrients to the body’s cells.
The solid part of blood includes red blood cells, white blood cells, and platelets.
(2:24)

10. Blood leaves the heart through blood vessels called arteries.
They lead to small vessels called capillaries.
They have thin walls and come into direct contact with every body cell. Nutrients, oxygen, and wastes move from areas of high concentration to areas of low concentration, meaning they move to where they are needed.

11. The Respiratory System
The respiratory system is a group of organs and tissues that exchanges oxygen and carbon dioxide between your body and the environment.

12. A muscle called the diaphragm helps pull air into your body
A muscle called the diaphragm helps pull air into your body. That air contains oxygen that you need.

13. The Path of Air In Nose or mouth Trachea Smaller and smaller tubes
Lungs (the main organ)

14. Working Together
The oxygen in the air that you inhale moves from the respiratory system into the blood.
Carbon dioxide moves from the blood into the respiratory system.
Carbon dioxide leaves the body when you exhale.
The exchange of gases takes place in air sacs in the lungs.
The thin walls of the capillaries and air sacs allow gases to move through them.

15. How does oxygen from the air get into your blood?
Air is breathed in through nose or mouth.
It travels through the trachea and smaller branching tubes into the lungs.
There, oxygen moves into the tiny blood vessels surrounding the air sacs.
Oxygen-rich blood then travels to the heart and is pumped to all cells in the body.

16. http://www.metacafe.com/watch/yt-bwXvqSqAgKc/respiratory_system/ (1:31)
(0:26)