Gas exchange is also known as respiration. It is the process by which oxygen is taken into the body and carbon dioxide is released. Respiration is essential for life, as it provides the body with the energy it needs to function.

Gas exchange occurs in the lungs. The lungs are made up of tiny air sacs called alveoli. The alveoli are lined with capillaries, which are tiny blood vessels. Oxygen from the air diffuses across the alveoli and into the capillaries. Carbon dioxide diffuses from the capillaries into the alveoli.

The oxygen-rich blood is then pumped by the heart to the rest of the body. The carbon dioxide-rich blood is pumped to the lungs, where it is exhaled.

Gas exchange is a vital process that ensures that the body has the oxygen it needs to function properly.