What do you call the tiny air sacs where gas exchange occurs in the lungs?

The tiny air sacs where gas exchange occurs in the lungs are called alveoli. These structures are crucial for respiration because they provide a large surface area for the exchange of oxygen and carbon dioxide between the lungs and the bloodstream. Each alveolus is surrounded by a network of tiny blood vessels known as capillaries, which facilitate this gas exchange process. Alveoli are specifically designed to maximize efficiency in transferring oxygen into the blood and removing carbon dioxide from it, making them vital for effective pulmonary function.

In contrast, the bronchi are the larger air passages that lead from the trachea to the lungs, the trachea itself is the windpipe that facilitates air passage from the throat to the lungs, and the pleura are the membranes surrounding the lungs and lining the chest cavity. These components play important roles in the respiratory system, but they do not participate directly in the gas exchange process that occurs specifically within the alveoli.