Each square inch of your skin contains approximately 35 miles of nerves. An adult body contains 75,000 miles of blood vessels, serving more than 60 billion body cells. Some vessels are so microscopically small that only one blood cell at the time can squeeze through. If all of your blood vessels could be cut open and laid side by side they would cover an area the size of a football field. During its 120 day life‑span, each blood cell makes about 75,000 round trips from the he