Cutaneous Respiration

Worms breathe in oxygen and breathe out carbon dioxide. But they don’t have lungs or a nose and they can’t breathe through their mouth. So they uniquely breathe through their skin. This happens when the air dissolves the mucus on their skin. Therefore in order for them to breathe they must stay moist. If a worm dries out, it will suffocate. As fresh air is taken in through the skin, oxygen is drawn into the worm’s circulatory system, and the worm’s heart pumps the oxygenated blood its head area. The movements of the worm’s body make the blood flow to the back end of the body, and the heart pumps the blood forward again. Carbon dioxide dissolves out of the blood back through the skin.