A single red blood cell takes only 60 seconds to travel through your entire body.

The human heart is an incredible pump that moves about 1.3 gallons of blood every single minute. Since the average adult has about 1.2 to 1.5 gallons of blood, almost every drop passes through the heart once every 60 seconds. This amazing cycle was first explained by a doctor named William Harvey in 1628.Blood does not move at the same speed everywhere. In the aorta, which is the biggest pipe leaving your heart, blood zooms at about 15 inches per second. But when it gets to the tiny capillaries, it slows down to a crawl. This slow speed is necessary so the cell can hand off oxygen and pick up waste from your body's tissues.Red blood cells are built perfectly for this non-stop travel. They do not have a center part called a nucleus, which makes them very floppy and flexible. This allows them to fold and squeeze through tiny tunnels that are even thinner than the cell itself. Over its short 120-day life, one cell will make this round trip about 170,000 times before it finally wears out.