Where does gas exchange primarily take place?

Gas exchange primarily occurs in the alveoli, which are tiny air sacs located at the end of the respiratory tree in the lungs. The alveoli provide a vast surface area and are surrounded by a network of capillaries, where oxygen and carbon dioxide are exchanged between the air in the alveoli and the blood. This process is vital for supplying oxygen to the bloodstream while removing carbon dioxide, a waste product of metabolism.

The structure of the alveoli facilitates efficient gas exchange due to their thin walls and the high permeability of their membranes, allowing gases to move easily between the lungs and the circulatory system. This is crucial for maintaining the body's respiratory needs and overall homeostasis.