Which part of the respiratory system is involved in the exchange of gases?

The alveoli are the primary structures in the respiratory system responsible for the exchange of gases. These tiny, balloon-like sacs are located at the end of the bronchioles in the lungs and are surrounded by a network of capillaries. When air reaches the alveoli, oxygen passes through their thin walls into the bloodstream, while carbon dioxide moves from the blood into the alveoli to be exhaled. This process, known as diffusion, is crucial for maintaining the body’s oxygen and carbon dioxide levels, making the alveoli essential for respiratory function.

The other parts mentioned, while integral to the respiratory system, serve different roles. The bronchi are the larger air passages that lead from the trachea to the lungs, the trachea is the windpipe that conducts air from the throat to the bronchi, and the pharynx is the throat area that serves as a pathway for both air and food. None of these structures are directly involved in the gas exchange process.