1. The Respiratory System

2. What is the system? Your respiratory system is made up of the organs in your body that help you to breathe. Respiration = Breathing. The goal of breathing is to deliver oxygen to the body and respiratory to take away carbon dioxide.

3. Why do you need to breathe? All the cells in your body require oxygen. Without it, they couldn't move, build, reproduce, and turn food into energy. In fact, without oxygen, they and you would die! How do you get oxygen? From breathing in air which your blood circulates to all parts of the body.

4. Why do we breathe? Your body is made up of tiny cells, each of which has a special job that keeps you alive. Every cell in your body needs a special gas called oxygen, that allows the cell to get energy from the food you eat. Oxygen in the air is brought into your lungs. That's when your blood picks it up and brings it to your cells.Your body is made up of tiny cells, each of which has a special job that keeps you alive. Every cell in your body needs a special gas called oxygen, that allows the cell to get energy from the food you eat. Oxygen in the air is brought into your lungs. That's when your blood picks it up and brings it to your cells. Another gas, called carbon dioxide is a waste product of your cells. It is very dangerous if it builds up in your body. Your blood carries the carbon dioxide from your cells to your lungs, to let you breathe out all the bad gas!Another gas, called carbon dioxide is a waste product of your cells. It is very dangerous if it builds up in your body. Your blood carries the carbon dioxide from your cells to your lungs, to let you breathe out all the bad gas!

5. more work = more breaths When we exercise, our cells are working harder, and they need more oxygen. They also produce more carbon dioxide. That's why you breathe faster when you exercise! You have probably noticed that when you're exercising, your heart beats more quickly. That's so that the blood can carry oxygen to your cells faster! Your heart and lungs work together to make sure every cell in your body gets enough oxygen. What do you think happens to the speed of our breathing when we're resting?

6. When you rest, your cells aren't working very hard, so they need less oxygen. They also produce less carbon dioxide. This means that you don't need to breathe as often as when you're moving around. Remember that because the heart and lungs work as a team, when your lungs are not working hard, your heart is not working hard either.

7. How the process works You breathe with the help of your diaphragm and other muscles in your chest and abdomen. These muscles literally change the space and pressure inside your body to accommodate breathing. When your diaphragm pulls down, it not only leaves more space for the lungs to expand but also lowers the internal air pressure. Outside, where the air pressure is greater, you suck in air in an inhale. The air then expands your lungs like a pair of balloons. When your diaphragm relaxes, the cavity inside your body gets smaller again. Your muscles squeeze your rib cage and your lungs begin to collapse as the air is pushed up and out your body in an exhale.

8. So, it all starts at the nose? Yup. About 20 times a minute, you breathe in. When you do, you inhale air and pass it through your nasal passages where the air is filtered, heated, moistened and enters the back of the throat. Interestingly enough, it's the esophagus or foodpipe which is located at the back of the throat and the windpipe for air which is located at the front. When we eat, a flap -- the epiglottis -- flops down to cover the windpipe so that food doesn't go down the windpipe. So -- back to breathing -- the air has a long journey to get to your lungs. It flows down through the windpipe, past the voice box or vocal cords, to where the lowermost ribs meet the center of your chest. There, your windpipe divides into two tubes which lead to the two lungs which fill most of your ribcage. Inside each of your sponge-like lungs, tubes, called bronchi, branch into even smaller tubes much like the branches of a tree. At the end of these tubes are millions of tiny bubbles or sacs called aleoli. Spread out flat, all the air sacs in the lungs of an adult would cover an area about the third of a tennis court.

9. What do these sacs do? They help perform an incredible magic act. Your air sacs bring new oxygen from air you've breathed to your bloodstream. They exchange it for waste products, like carbon dioxide, which the cells in your body have made and can't use.

10. How does this exchange work? With the help of the red blood cells in your bloodstream. Your red blood cells are like box cars on train tracks. They show up at the sacs at just the right time, ready to trade in old carbon dioxide that your body's cells have made for some new oxygen you've just breathed in. In the process, these red blood cells turn from purple to that beautiful red color as they start carrying the oxygen to all the cells in your body.

11. But what happens to the carbon dioxide? It goes through the lungs, back up your windpipe and out with every exhale. It's a remarkable feat, this chemical exchange and breathing in and out. You don't have to tell your lungs to keep working. Your brain does it automatically for you.

12. Parts of the respiratory system Lungs Trachea Bronchi Diaphragm

13. Lungs The lungs are the main organs of the respiratory system. In the lungs oxygen is taken into the body and carbon dioxide is breathed out. The red blood cells are responsible for picking up the oxygen in the lungs and carrying the oxygen to all the body cells that need it. The red blood cells drop off the oxygen to the body cells, then pick up the carbon dioxide which is a waste gas product produced by our cells. The red blood cells transport the carbon dioxide back to the lungs and we breathe it out when we exhale.

14. Trachea The trachea (TRAY-kee- uh} is sometimes called the windpipe. The trachea filters the air we breathe and branches into the bronchi.

15. Bronchi The bronchi (BRAHN-ky) are two air tubes that branch off of the trachea and carry air directly into the lungs

16. Diaphragm Breathing starts with a dome-shaped muscle at the bottom of the lungs called the diaphragm (DY-uh- fram). When you breathe in, the diaphragm contracts. When it contracts it flattens out and pulls downward. This movement enlarges the space that the lungs are in. This larger space pulls air into the lungs. When you breathe out, the diaphragm expands reducing the amount of space for the lungs and forcing air out. The diaphragm is the main muscle used in breathing.

17. Factoids Your lungs contain almost 1500 miles of airways and over 300 million alveoli. Every minute you breathe in 13 pints of air. Plants are our partners in breathing. We breathe in air, use the oxygen in it, and release carbon dioxide. Plants take in carbon dioxide and release oxygen. Thank goodness! People tend to get more colds in the winter because we're indoors more often and in close proximity to other people. When people sneeze, cough and even breathe -- germs go flying! http://yucky.kids.discovery.com/flash/body/pg000138.html

18. When you are sleepy or drowsy the lungs do not take enough oxygen from the air. This causes a shortage of oxygen in our bodies. The brain senses this shortage of oxygen and sends a message that causes you to take a deep long breath---a YAWN. Why do we yawn?

19. Why do we sneeze? Sneezing is like a cough in the upper breathing passages. It is the body's way of removing an irritant from the sensitive mucous membranes of the nose. Many things can irritate the mucous membranes. Dust, pollen, pepper or even a cold blast of air are just some of the many things that may cause you to sneeze.

20. What Causes Hiccups? Hiccups are the sudden movements of the diaphragm. It is involuntary --- you have no control over hiccups, as you well know. There are many causes of hiccups. The diaphragm may get irritated, you may have eaten to fast, or maybe some substance in the blood could even have brought on the hiccups. http://www.lung.ca/children/grades4_6/respiratory/index.html