What is the primary function of alveoli in the lungs?

The primary function of alveoli in the lungs is to serve as the gas exchange surface. Alveoli are tiny, balloon-like structures that provide a large surface area for the exchange of gases between the air and the blood. This is where oxygen from the inhaled air diffuses into the bloodstream, and carbon dioxide is released from the blood to be exhaled. The design of the alveoli, with their thin walls and extensive capillary networks, maximizes efficiency for this vital exchange, ensuring that oxygen can quickly enter the body and carbon dioxide can be removed.

Oxygen storage is not a primary function of the alveoli; rather, their role is centered on exchanging gases rather than storing them. The transport of air is carried out by the respiratory system through various structures like the trachea and bronchi, leading to the alveoli, but it is not a function of the alveoli themselves. The production of ATP occurs within the cells through cellular respiration, which involves oxygen and glucose, but is not a direct function of the alveoli in the lungs. Hence, the role of the alveoli is crucially focused on gas exchange, making them essential for respiration and overall cellular function.