What role do alveoli play in respiration?

Alveoli are tiny air sacs located in the lungs, and their primary role in respiration is to facilitate the exchange of gases—specifically, oxygen and carbon dioxide—between the air and the bloodstream. This process occurs through a thin alveolar-capillary membrane, which allows oxygen from inhaled air to diffuse into the blood while carbon dioxide, a metabolic waste product, is expelled from the blood into the alveoli to be exhaled.

The structure of alveoli is critical for this function; they have a large surface area due to their numerous presence in the lungs, and they are lined with a thin layer of epithelial cells. This design maximizes efficiency in gas exchange, ensuring that the body receives adequate oxygen to function while removing carbon dioxide effectively.

Through this mechanism, alveoli play an essential role in maintaining the body’s respiratory needs, supporting cellular metabolism, and overall homeostasis.