It takes about 20 seconds for a red blood cell to circle the whole body.
102
It would take about 1,200,000 mosquitoes to fully drain the average human body of blood.
217
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Your body is creating and killing about 2.4 million red blood cells per second.
17
The human brain is very soft, having a consistency similar to soft gelatin or firm tofu.
13
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
There are times when you're walking that the pressure on your feet exceeds your body weight, and when you're running, it can be three or four times your weight.
62