What is the role of alveoli in the respiratory system?

The role of alveoli in the respiratory system is primarily to facilitate gas exchange. Alveoli are tiny air sacs located at the end of the bronchioles in the lungs, and they are surrounded by a network of capillaries. This structure is crucial because it allows oxygen from the air to pass into the blood while simultaneously enabling carbon dioxide, a waste product, to be removed from the blood and expelled from the body.

The thin walls of the alveoli and the close proximity of the capillaries create an efficient area for diffusion. Oxygen moves from the alveoli, where the concentration is higher, into the blood in the capillaries, where the concentration is lower. Conversely, carbon dioxide moves from the blood, where it is in higher concentration, into the alveoli to be exhaled.

This gas exchange process is vital for maintaining the body’s oxygen levels and removing carbon dioxide, thus playing an essential role in overall respiratory function and homeostasis.