Alveoli

Alveoli are tiny, balloon-like air sacs located in the lungs where gas exchange occurs. They are the final stage of the respiratory system, where oxygen from the air we breathe passes into the blood, and carbon dioxide, a waste product, is expelled from the blood into the lungs to be exhaled. Alveoli are surrounded by a network of capillaries, which are small blood vessels. Their large surface area and thin walls make them efficient for this exchange process, playing a crucial role in keeping our bodies oxygenated and healthy.