How do lungs work?

The lungs are a pair of organs in the human body that are responsible for exchanging oxygen and carbon dioxide between the air and the blood. They are located in the chest and are made up of tiny air sacs called alveoli, which are surrounded by a network of blood vessels.

The process of breathing (respiration) involves the inhalation of oxygen and the exhalation of carbon dioxide. When you inhale, the muscles in your chest and diaphragm contract and expand, causing your lungs to fill with air. This air travels down the trachea (windpipe) and into the bronchi, which branch off into smaller tubes called bronchioles. The bronchioles end in the alveoli, where oxygen and carbon dioxide are exchanged with the blood.

Oxygen from the air diffuses across the walls of the alveoli and into the blood vessels, where it is carried to the body's cells. At the same time, carbon dioxide, a waste product of cellular metabolism, diffuses from the blood vessels into the alveoli and is exhaled out of the body.

The process of respiration is regulated by the respiratory center in the brain, which controls the rate and depth of breathing. When the body needs more oxygen, such as during exercise, the respiratory center increases the rate and depth of breathing to bring in more oxygen. Similarly, when the body has too much carbon dioxide, the respiratory center increases the rate and depth of breathing to exhale more carbon dioxide.