The lungs work with the heart to oxygenate blood. They do this by filtering the air a person breathes, then removing excess carbon dioxide in exchange for oxygen.

Several parts of the lungs help the body take in air, filter it, and then oxygenate the blood. These are:

  • The left and right bronchi: The trachea splits into these tubes, which extend into the lungs and have branches. These smaller bronchi split into even smaller tubes called bronchioles.
  • The alveoli: The alveoli are tiny air sacs at the end of the bronchioles. They work like balloons, expanding when a person inhales and contracting when they exhale.
  • The blood vessels: There are numerous blood vessels in the lungs for carrying blood to and from the heart.

With extensive medical care, a person can live without one lung, but they cannot survive with no lungs.

The diaphragm, which is a thick band of muscle directly under the lungs, helps the lungs expand and contract when a person breathes.