1. What is the Respiratory System?
Chapter 3 Lesson 2
What is the Respiratory System?

2. What is the job of the respiratory system?
The respiratory system carries gases between the outside air and your blood.
Your respiratory system is at work whenever you smell, sing, talk, laugh, or breathe.

3. The parts of the respiratory system include:
Trachea
Bronchioles
Air sacs
Diaphragm
Larynx

4. A closer look at the parts
The trachea is a tube that carries air from the larynx to the lungs.
The larynx contains your vocal cords.
The bronchioles are smaller tubes from bronchi that branch out from the trachea.
The diaphragm is a muscle in the bottom of the chest area that contracts with breathing.
Air sacs are where oxygen enters the blood and carbon dioxide leaves the blood. They are also called alveoli.

5. More About the Air Sacs
Air sacs walls are covered with a web of tiny blood vessels called capillaries.

6. Larynx, Trachea, and Bronchi

7. Bronchioles, Air Sacs, and Diaphragm

8. How we breathe
Several muscles work together when you breathe. When you inhale, your diaphragm contracts and moves down, making more space in your chest. Your rib muscles may also pull your rib cage up and out, making still more space. Air quickly rushes into the lungs and takes up the new spaces. When your diaphragm and rib muscles relax, they push air out of the lungs.
Look at the picture on the next slide to see how we breathe.

10. How do the respiratory system and the circulatory system work together?
In humans, the respiratory and circulatory systems work together to get oxygen to the cells.
The respiratory system gets air all the way to your air sacs where the blood (circulatory system) picks it up there and carries it all to your cells.
In the air sac, oxygen leaves the lungs and enters the blood and carbon dioxide leaves the blood and enters the lungs.

11. Respiratory and Circulatory Systems working together continued….
Holding your breath causes carbon dioxide to build up in your blood. Your brain can sense this, so it sends a message to the diaphragm and rib muscles telling them to breathe.

12. Diseases of the Respiratory System
Cold- runny nose, stuffy nose, sneezing
Influenza- cough, sore throat, stuffy nose, fever
Pneumonia- cough, chest pain, shortness of breath, fever
Tuberculosis- cough, fever, wheezing
Lung cancer- lung cells grow incorrectly and very quickly

13. What have we learned today?
The respiratory system carries what between the outside air and your blood?
Name the parts of the respiratory system.
What cover the walls of air sacs?
How do the respiratory system and circulatory system work together?
Hold your breath for ten seconds. What just built up in your blood?
Name 2 diseases of the respiratory system.