What are the main functions of the lungs?
The lungs are generally the respiratory organs of the human body, primarily responsible for gas exchange—supplying oxygen essential for life and eliminating metabolic waste gases such as carbon dioxide. Specifically:
Through respiratory movements, including inhalation and exhalation, the lungs facilitate gas exchange between the body and the external environment. During inhalation, lung volume increases, allowing fresh air to enter the alveoli via the airways. Oxygen in the air diffuses across the alveolar and capillary walls into the bloodstream, where it binds to hemoglobin in red blood cells and is transported to tissues and organs throughout the body to support metabolism. During exhalation, lung volume decreases, expelling waste gases such as carbon dioxide from the blood through the capillary and alveolar walls out of the body. This process maintains relative stability of the internal environment and prevents complications such as acidosis caused by the accumulation of waste gases. In addition, the lungs also perform functions including defense, metabolism, immunity, and blood storage. They filter and remove harmful substances from inhaled air, protecting the body from environmental pollutants.
To maintain lung health, it is important to develop good lifestyle habits, avoid harmful environments, strengthen bodily functions, and prevent common diseases.