How the Lungs Work
Cystic fibrosis is a genetic disease that can drastically affect lung function. Here, you can get an overview of how each part of the respiratory system works, so you can better understand the disease.
What the lungs do
- Healthy lungs take in fresh oxygen and get rid of carbon dioxide and other gaseous waste products so that other parts of the body can function properly.
Trachea and bronchi
- When you breathe in, the mucus membranes
in your mouth and nose warm and moisten the air that passes through your throat
and into your trachea or
Your trachea divides into the left and right bronchi, like a tree branch. Each bronchus divides again and again, becoming narrower and narrower.
- These branches lead to millions of alveoli, which are small, thin air sacs that look like clusters of balloons. When you breathe in, the "balloons" expand. When you breathe out, the "balloons" relax and air is released.
The oxygen you breathe in binds to hemoglobin,
a protein in your blood that gives
red blood cells their color, and is carried from your lungs to body tissues.
Hemoglobin also has carbon dioxide bound to it, which it passes into the alveoli
within a fraction of a second each time you inhale.
When you exhale, the carbon dioxide leaves the alveoli, and the oxygen-rich blood returns to your heart. This exchange of gases allows your body to release carbon dioxide as a waste product and retain the oxygen necessary for your tissues and organs to function properly.
Feeling well is only part of the story.
Even if you (or your child) feels well, cystic fibrosis may still be active in the lungs and can cause damage. That is because CF affects the small airways deep in the lungs at first and may not immediately affect lung function. As the effects of CF reach the larger airways, symptoms such as coughing or difficulty breathing may increase.
Pulmozyme may be an essential part of your fight against CF — in those with mild to moderate CF*, Pulmozyme may help improve lung function and reduce the risk of respiratory tract infection.
* Patients had an FVC≥40% predicted. FVC stands for forced vital capacity, a test that shows how well the lungs work. To do the test, patients usually take the deepest breath they can. Then they exhale into a sensor for as long as they can. The amount of air they exhale is their FVC score.