Images and How it Works

The below is a diagram of the human respiratory system. Air from the mouth and nose flows down the trachea(windpipe) and into the lungs. The air then goes down one of two bronchi(tubes that the trachea splits into) and then into one of many bronchioles- small bronchi. From the bronchioles, the air goes into the alveoli(tiny air sacks) where it diffuses into capillaries, which lead to arterioles, which lead to arteries leading to the heart. The oxygenated blood circulates through the body, leading back to the heart and lungs. Various problems with the respiratory system can lead to asthma. Smoking can result in "black lung", which can lead to lung cancer and death.