How Do the Lungs Work?

The lungs are a pair of sponge-like organs located inside the rib cage. The right lung has three sections, called lobes, and the left lung has two. The airways are a series of hollow tubes, which allow oxygen to enter into the lung tissue as we breathe.

As you breathe in, oxygen enters the windpipe (trachea), goes through the airways (bronchus and bronchioles) and into small sacs called alveoli. The alveoli are surrounded by blood vessels. The oxygen crosses into the bloodstream from the alveoli and is then carried to the rest of the body. Oxygen is needed to allow cells in our body to function normally. The heart pumps the blood, which carries the oxygen.

 A thin membrane covers the surface of the lungs and is called the visceral pleura. A membrane also lines the chest wall and is called the parietal pleura. These membranes allow the lungs to slide as we breathe in and out.

 The lymphatic system is a network of vessels, which filter bacteria and other foreign material, in order to help fight infection or disease. Tumor cells can spread (metastasize) through the blood vessels and lymphatic system. Lymph nodes are a part of the lymphatic system. They are nodules along the vessels of the lymphatic system that filter germs and other foreign material such as cancer cells. These nodes swell when cells become trapped.