What structure plays a vital role in the exchange of gases in the lungs?

The alveoli are the small, balloon-like structures in the lungs where the actual exchange of gases takes place. They provide a large surface area for this exchange due to their numerous tiny sacs that increase the efficiency of oxygen absorption and carbon dioxide release. Each alveolus is surrounded by a network of capillaries, allowing oxygen to diffuse from the alveoli into the blood and carbon dioxide to diffuse from the blood into the alveoli to be exhaled. This process is crucial for respiratory function, making alveoli integral to gas exchange in the respiratory system.

In contrast, the bronchi are the larger air passages that lead from the trachea to the lungs, facilitating airflow but not directly involved in the gas exchange process. The trachea is the windpipe that connects the throat with the bronchi and primarily serves as a conduit for air. The diaphragm, a muscle that aids in breathing by contracting and relaxing to move air in and out of the lungs, does not directly participate in the gas exchange itself.