Breathing+Video+CC

How do we breathe?

 * Breathing is the act of inhaling and exhaling air
 * the diaphragm is a muscle that controls inhaling and exhaling
 * Inhaling is when our diaphragm contracts
 * Exhaling is when the diaphragm relaxes
 * The air we breathe is made up of 78 % Nitrogen, about 18 % Oxygen, and 4 % Carbon Dioxide
 * Air enters through our nasal cavity (our nose and mouth)
 * Our nose has small hairs (cilia) in it which help to filter some of the air
 * mucus also helps filter
 * Then enters the trachea/windpipe which is a part of our throat
 * Trachea splits in to two bronchial tubes
 * each bronchial tube leads to one of your lungs
 * mucus, produced by mucus glands, also coats your trachea and lungs
 * mucus is the cleaning system of the lungs
 * in the lungs there are alveoli at the end of the bronchial tubes
 * these alveoli are where the oxygen is transfered from the lungs into the blood system
 * during the same time and in the same place, carbon dioxide is released from the blood system into the lungs
 * the carbon dioxide is then released back into the air when we breathe out
 * once in the blood system, the heart pumps the blood through out the whole body, delivering oxygen everywhere
 * we breathe about 16 kilograms of air each day