Giant Microbes Lung Keyring
Your two lungs are the main organs of the respiratory system. Lungs are large, filling most of your chest. Lungs rely on your rib muscles and the diaphragm to expand and deflate. Air travels down your trachea into two bronchi, bronchioles and millions of alveoli. These cluster of tiny airbags provide a tennis-court sized area to maximize gas exchange. This is where the magic happens, oxygen passes into your blood and carbon dioxide flows out.