It takes about 20 seconds for a red blood cell to circle the whole body.
102
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
One human hair can support 3 ounces.
191
Your body is creating and killing about 2.4 million red blood cells per second.
17
Your heart will pump about 212 million liters in its lifetime.
26
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193
When you take a step, you are using up to 200 muscles.
886