The air sacs where gas exchange occurs are known as what?

The air sacs where gas exchange occurs are known as alveoli. These tiny, balloon-like structures are located at the end of the bronchioles in the lungs. The primary function of alveoli is to facilitate the exchange of oxygen and carbon dioxide between the air in the lungs and the blood in the surrounding capillaries. The walls of the alveoli are extremely thin and are covered in a network of capillaries, which allows for efficient diffusion of gases.

Oxygen from the inhaled air passes through the alveolar walls into the bloodstream, while carbon dioxide, a waste product of metabolism, diffuses from the blood into the alveoli to be exhaled. This crucial process is fundamental to respiration and is essential for supplying the body with the oxygen it needs while removing carbon dioxide.

In contrast, bronchi are the large air passages that lead from the trachea (windpipe) to the lungs, bronchioles are smaller airways branching from the bronchi that lead to the alveoli, and the pharynx is the muscular tube that connects the nasal and oral cavities to the larynx and esophagus. None of these structures participate directly in the gas exchange process that occurs in the alveoli.