For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
It takes about 20 seconds for a red blood cell to circle the whole body.
102
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
Enamel is hardest substance in the human body.
61
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
Chewing gum boosts your brain power.
285
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193
Women have about four times as many foot problems as men; lifelong patterns of wearing high heels often are the culprit.
111