What is the order of parts/openings in which air passes on its way to the lungs?
As you breathe in, your diaphragm contracts and flattens out. This allows it to move down, so your lungs have more room to grow larger as they fill up with air. Your rib muscles also lift the ribs up and outward to give the lungs more space. you inhale and the air heads down your trachea, or windpipe. On the way down the windpipe, tiny hairs called cilia move gently to keep mucus and dirt out of the lungs. The air then goes through the series of branches in your lungs, through the bronchi and the bronchioles. The air finally ends up in the alveoli. As these millions of alveoli fill up with air, the lungs get bigger. It’s the alveoli that allow oxygen from the air to pass into your blood. Oxygen passes through the walls of each alveolus into the tiny capillaries that surround it. The oxygen enters the blood in the tiny capillaries, hitching a ride on red blood cells and traveling through layers of blood vessels to the heart. The heart then sends the oxygenated blood out to all the cells
