Gas exchange

Gas exchange is the process where oxygen from the air we breathe enters our bloodstream, and carbon dioxide, a waste product, leaves the blood to be exhaled. This occurs in tiny air sacs in the lungs called alveoli, which are surrounded by small blood vessels. Oxygen passes through the thin walls of alveoli into the blood because there’s a higher concentration of oxygen in the alveoli than in the blood. Conversely, carbon dioxide moves from the blood into the alveoli to be expelled during exhalation. This exchange is vital for providing oxygen to body tissues and removing carbon dioxide waste.