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
The human brain doesn't stop developing until about 25 years old.
102
Most of us have microscopic, worm like mites named Demodex that live in our eyelashes and have claws and a mouth.
-137
Women have about four times as many foot problems as men; lifelong patterns of wearing high heels often are the culprit.
111
The average sperm cell swims at 8 inches per hour.
76
Every year your body replaces 98% of your atoms.
119
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99