The circulatory path refers to the path that blood takes while travelling through different tissues and organs of the body to supply them with nutrients and oxygen. Since, in humans the blood comes back to the heart twice before completing one cycle, it is known as double circulation. Double circulation is an extremely important and efficient mode of circulation of blood. It ensures proper blood circulation within the body without getting oxygen-rich blood mixed with the deoxygenated one. Furthermore, this separation between the two types of blood supplies oxygen to blood cells and increases blood flow.