The Air We Breathe - A Resource Guide To The Respiratory System
There are many special systems in our bodies that help us to live and function properly. One of these very important systems is called the respiratory system and it controls the way we process air to breathe. But why is breathing necessary? Quite simply, the tiny cells that make up every part of our body use oxygen in the same way that cars use fuel. Without oxygen, the cells would stop working and die.
Breathing starts with our noses. We take in air through our noses (and sometimes through our mouths as well) and the air moves all the way to the back of our throats. While it moves, it becomes moist and warm, and many particles of dirt are removed. The air now has to pass down into the throat and then even further down into our lungs. We each have two lungs and they are protected by our ribcages. Our chest muscles help to automatically process air by expanding and contracting the lungs. It uses the basic principles of air pressure so that we breathe in air when the air pressure inside our lungs is low and we breathe out air with the pressure inside our lungs is high.
Each lung is filled with masses of bronchi which are tubes that distribute the air. At the end of the bronchi are a series of tightly-packed smaller tubes with tiny bags known as alveoli. Some parts of the tubes can be as thin as hairs but they serve very vital functions. The alveoli are like little factories; they take the good, clean oxygen and transfer it into the blood and at the same time, they help to remove carbon dioxide and other gases that we don't need. Once the oxygen is in the blood, thousands of red blood cells help to distribute it to all the different parts of the body. When the blood is full of oxygen, it is a bright red color and when it has almost no oxygen, it turns purple. Finally, the carbon dioxide goes back up through the bronchi, up the throat and out of our noses. The beauty of our respiratory systems is that all of this work happens automatically thousands of times everyday!
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