It takes about 20 seconds for a red blood cell to circle the whole body.
102
An average heart beats 100,000 times a day, pumping some 2,000 gallons of blood through its chambers. Over a 70-year life span, that adds up to more than 2.5 billion heartbeats.
73
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
The human brain uses approximately as much energy as a 10 watt light bulb.
120
When you take a step, you are using up to 200 muscles.
886
When you get goosebumps and your hair stands, the hair helps to trap air, making you feel warmer by keeping in your body heat.
46
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
One human hair can support 3 ounces.
191