This process begins when you breath through your nose, and into your lungs.Before the oxygen gets into your lungs the air passes through your nassal cavity,oral cavity,pharynx,larynx,trachea/windpipe,bronchies and then it gets to the lungs.When you breathe in, the lungs expand and make the diaphgram go down so the lungs can have space because when you breathe in they get bigger. The diaphgrm helps you breathe. You breath about 18 to 20 times per minutes aproximately. When we breath the lungs get bigger and that makes that the diaphgram pushes down. When the oxygen that you breathe in passes through your lungs it goes into your arteries . There the red blood cells carry the oxygen all around your body. There is a tissue in your body that uses oxygen to turn it into energy and heat, after that it burns it like fuel. After the tissue uses the oxygen turned into a sort of fuel it turns it into carbon dioxide and sends it back to the lungs by the help of the veins. When the carbon dioxide is in the lungs you exhale or breathe out becouse your lungs are so full of air. The corbon dioxide is blown out of your lungs through your nose and mouth. When we breathe out the diaphgram and rib relax.

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Here are some videos which shows you about the breathing process