All photos are courtesy of Unsplash
Using an average of 80 beats per minute, the heart beats around 115,000 times a day. Although a typical adult human body contains near to 5 litres of blood, the heart pumps the equivalent of 7,500 litres of blood a day through around 60,000 miles of blood vessels. That is equivalent to more than twice the circumference of the earth’s surface, and some of the blood vessels are as thin as 5 microns — that is 5 thousandths of a millimetre, thinner than a human hair.