How Your Lungs Work

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How Your Lungs Work

In order to survive your body needs oxygen from the air you breathe. The lungs are designed to absorb oxygen from the air and transfer it into the bloodstream and then to remove waste gases, such as carbon dioxide.
When you breathe air in through your nose or mouth, it travels down the back of your throat (pharynx), passes through your voice box (larynx), and into your windpipe (trachea).

Your trachea is divided into two air passages (bronchial tubes). One bronchial tube leads to the left lung, the other to the right lung.

The right lung has three sections, called lobes, and is a little larger than the left lung, which has two lobes. The bronchial tubes divide into smaller air passages (bronchi), and then into bronchioles. The bronchioles end in tiny air sacs called alveoli, where the oxygen and carbon dioxide are exchanged.

After absorbing oxygen, the blood leaves the lungs and is carried to the heart. Then, it is pumped through your body to provide oxygen to the cells of your tissues and organs. When the oxygen is used by the cells, carbon dioxide (CO2) is produced and transferred to the blood. Your blood carries the CO2 back to your lungs, which removes it when you breathe out.

The respiratory system has built-in methods to prevent harmful substances from entering the lungs:

• Your nose moistens and warms the air.
• The hair (cilia) in your nose helps filter out large particles.
• Mucus produced by cells in the trachea and bronchial tubes keeps air passages moist and aids in trapping dust, bacteria, and other substances.
• Cilia in the air passages move in a sweeping motion upwards towards the throat and mouth to get the mucus and bacteria etc out of the lungs.

Healthy lungs are made of a spongy, pinkish-greyish tissue. Lungs that have become polluted with harmful particles, like smoke, appear to have blackened spots on the surface.

Healthy lungs are elastic so they can expand when you breathe in. In contrast, a disease such as emphysema causes the lungs to loose their elasticity. When a lung can no longer expand properly or transfer oxygen to the blood, that person has difficulty breathing and tires easily. Other difficulties can occur because the tissues and organs aren't getting the oxygen they need.

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