How long does it taker for blood to make its round-trip journey to and from the heart?

This mind-boggling trip takes less than a minute! The pumping heart muscle loses no time - it never stops. In a healthy body there are no traffic jams, since arteries and veins are one-way streets. Thanks to very efficient valves (which act like trapdoors),the blood can flow only one way, make a quick side trip to the lungs for an exchange of air,and then start on its way again.