Question

.How is mixing of oxygen-rich and carbon di oxide rich blood prevented in humans?

Answer 1

The oxygen rich blood is carried in separate blood vessels known as artery. The only artery that carries de-oxygenated blood is the pulmonary artery in the heart.

The de-oxygenated bloods carried in another type of blood vessel known as veins. The only exception is the pulmonary vein that carries oxygen rich blood from the lungs to the heart.

Thus, the intermixing of oxygenated and de-oxygenated blood is prevented.