3. <ul><li>All animals need oxygen to live. Land animals get oxygen from the air. Without the oxygen in the air we cannot survive more than a few minutes. Breathing happens automatically, we do not have to even think about it. </li></ul><ul><li>We breathe in order to take oxygen into our bodies and get rid of carbon dioxide . The oxygen is carried in the blood to all the body's cells. The air we breath out has 100 times more carbon dioxide than the air we breath in. </li></ul>Respiratory System
4. Lungs <ul><li>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. </li></ul>
5. Parts of the Circulatory System <ul><li>Trachea The trachea (TRAY-kee-uh} is sometimes called the windpipe. The trachea filters the air we breathe and branches into the bronchi. Bronchi The bronchi (BRAHN-ky) are two air tubes that branch off of the trachea and carry air directly into the lungs. </li></ul>Diaphragm Breathing starts with a dome-shaped muscle at the bottom of the lungs called the diaphragm The diaphragm is the main muscle used in breathing.
8. Interesting facts <ul><li>Why Do I 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. </li></ul><ul><li>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. </li></ul><ul><li> </li></ul>