Alveolus
Alveolus explained in an easy to understand way:
Imagine trying to quickly cool a steaming cup of coffee by blowing on it. Just like you blow gently across the surface to let cool air mingle with the hot steam, alveoli in the lungs facilitate a crucial exchange. The alveoli are like the surface of the coffee, where their thin walls allow oxygen to move into the blood and carbon dioxide to leave, similar to how air helps steam disperse, cooling the coffee. This exchange at the alveoli is essential for balancing gases, just as blowing on coffee cools it down for a perfect sip.
Practice Version
Alveolus: Tiny, thin-walled sacs in the lungs where oxygen and carbon dioxide are exchanged between air and the blood. Alveolus. An alveolus is a small air sac in the lungs that allows for gas exchange with the blood.