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
Chewing gum boosts your brain power.
285
It would take about 1,200,000 mosquitoes to fully drain the average human body of blood.
217
The average sperm cell swims at 8 inches per hour.
76
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
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18