What is the primary function of alveoli in the lungs?

The primary function of alveoli in the lungs is to facilitate gas exchange. Alveoli are tiny air sacs located at the end of the respiratory bronchioles, where the crucial process of respiration occurs. They are surrounded by a network of capillaries, allowing for the exchange of oxygen and carbon dioxide between the air we breathe and the blood.

When oxygen enters the alveoli during inhalation, it diffuses through the thin walls of the alveoli and into the capillaries, where it binds to hemoglobin in red blood cells for transport to tissues throughout the body. Simultaneously, carbon dioxide, which is a waste product of cellular metabolism, diffuses from the blood into the alveoli to be exhaled. This efficient gas exchange process is essential for maintaining the body’s oxygen levels and removing carbon dioxide, thus playing a critical role in respiration and overall respiratory health.

While transporting oxygen, supporting lung structures, and warming air are important aspects of the respiratory system, they do not capture the central role of alveoli, which is explicitly focused on the exchange of gases necessary for effective respiration.