How the lungs work

The main job of the lungs is to help you breathe. The lungs bring oxygen-rich air into the body and remove a waste gas called carbon dioxide (CO2).1 The lungs also help protect the body from dust, bacteria, and other harmful substances in the air.1

Learn more

How the lungs work

How the lungs work

Air enters the body through the nose or mouth, travels through the larynx (voice box) and down the trachea (windpipe) into the bronchial tubes that lead into the lungs.1

How the lungs work

How the lungs work

The bronchial tubes branch out into smaller and smaller tubes called bronchioles. At the end of the bronchioles are tiny air sacs called alveoli. The alveoli are lined with blood vessels called capillaries.1

How the lungs work

How the lungs work

Red blood cells that pass through the capillaries help move oxygen (O2) from the air through the bloodstream to the heart. The heart pumps the oxygen-rich blood out to the rest of the body.2

At the same time, carbon dioxide (CO2) your body no longer needs moves from the capillaries into the alveoli. This waste gas is pushed out of the lungs when you breathe out.2

How the lungs work

How the lungs work

A thin film of airway surface liquid coats the inside of the lungs and keeps them moist. The airway surface liquid has a layer of mucus, a sticky substance that traps dust and germs that enter the lungs. This helps to protect the lungs from infection.3

How the lungs work

How the lungs work

Small hair-like structures called cilia clear dust and germs trapped in the mucus by pushing it up out of the lungs.4

How the lungs work

How the lungs work

A protein called CFTR* helps keep the right balance of water (H2O) and salt (NaCl) on the surface of the lungs.5 This helps keep mucus thin and slippery.4

  • *CFTR = Cystic fibrosis transmembrane conductance regulator

How the lungs work

What is CAYSTON?

CAYSTON is a prescription inhaled antibiotic used to improve breathing symptoms in people with cystic fibrosis (CF) who have a lung infection due to Pseudomonas aeruginosa (Pa). CAYSTON is not a treatment for infections caused by other bacteria or viruses, such as the common cold. CAYSTON is used only with the Altera® Nebulizer System. It is not known if CAYSTON is safe and effective in children under the age of 7 or in patients with FEV1 <25% or >75% predicted.