What is the function of the lungs in the respiratory system?

The lungs serve a critical role in the respiratory system primarily by facilitating the exchange of gases, which involves holding oxygen and releasing carbon dioxide. During inhalation, oxygen from the air enters the alveoli (tiny air sacs in the lungs), where it diffuses into the bloodstream. Simultaneously, carbon dioxide, a waste product of metabolism, moves from the blood into the alveoli to be exhaled. This exchange is essential for maintaining proper oxygen levels in the body and removing carbon dioxide, which is vital for healthy bodily functions.

Storing carbon dioxide, producing oxygen, and filtering air pollutants are not primary functions of the lungs. While the lungs do participate in minor filtration of air, their main function is not specifically to filter air pollutants, nor do they produce oxygen, as oxygen is absorbed during the gas exchange process.