What role do alveoli play in the respiratory system?

Alveoli serve a critical role in the respiratory system by facilitating the exchange of gases between the air and the bloodstream. These tiny, balloon-like structures are located at the end of the bronchioles and provide a large surface area for gas exchange. The thin walls of the alveoli allow oxygen from the inhaled air to diffuse into the capillaries surrounding them, where it binds to hemoglobin in red blood cells. Simultaneously, carbon dioxide, which is a waste product of metabolism, diffuses from the blood into the alveoli to be expelled from the body during exhalation. This exchange of oxygen and carbon dioxide is essential for sustaining life, as it ensures that the body receives the oxygen needed for cellular processes and removes carbon dioxide to maintain the acid-base balance in the body.