Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
The human brain is very soft, having a consistency similar to soft gelatin or firm tofu.
13
If your DNA was stretched out it would reach to the moon 6,000 times.
256
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
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
The largest cell in the human body is the female egg and the smallest is the male sperm.
682