What is the function of the alveoli in the lungs?

The primary function of the alveoli in the lungs is gas exchange. Alveoli are tiny, balloon-like structures located at the ends of the respiratory bronchioles and are the site where oxygen enters the blood and carbon dioxide is removed. They are surrounded by a network of capillaries that allow for this exchange to occur efficiently due to the thin walls of both the alveoli and the capillaries.

When air is inhaled, it travels down the bronchial tree to the alveoli, where the oxygen in the air passes through the alveolar walls into the bloodstream. Simultaneously, carbon dioxide, which is a waste product of metabolism, moves from the blood into the alveoli to be exhaled. This process is crucial for maintaining the body's oxygen levels and removing carbon dioxide, which is vital for homeostasis.

While other functions of the respiratory system include producing mucus to trap particles, filtering air, and playing a role in regulating blood pH through the balance of gases, the specific and primary role of the alveoli is focused on gas exchange.