What is significant about the alveoli in the lungs?

The alveoli in the lungs hold significant importance as the primary site of gas exchange in the respiratory system. They are tiny, balloon-like structures that provide a large surface area for the diffusion of gases. Each alveolus is surrounded by a network of capillaries, which allows oxygen from the inhaled air to pass into the bloodstream and carbon dioxide, a waste product of metabolism, to move from the blood into the alveoli, where it is then exhaled.

The structure of the alveoli is specifically designed for this purpose, featuring thin walls (made up of a single layer of cells) that facilitate efficient gas exchange. The large surface area created by their numerous and clustered arrangement further enhances this process, making the alveoli essential for maintaining adequate oxygen levels in the blood and removing carbon dioxide from the body.