Alveoli maximize gas exchange in the lungs primarily by creating a large surface area.
The alveoli are tiny air sacs at the end of the bronchial tubes, and there are approximately 300 million of them in the human lungs, providing a vast surface area for gas exchange. This large surface area enhances the diffusion of oxygen into the blood and carbon dioxide out of the blood, facilitating efficient respiratory function.
While pressure changes in the lungs (due to inhalation and exhalation) also play a crucial role in drawing air in and out, it is the large surface area of the alveoli that is the most critical factor for maximizing gas exchange. The other options, such as producing immune cells and storing oxygen, do not directly pertain to the function of alveoli in gas exchange.