Your body is creating and killing about 2.4 million red blood cells per second.
17
The average person's skin weighs twice as much as their brain.
131
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
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
The average sperm cell swims at 8 inches per hour.
76