For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
The average sperm cell swims at 8 inches per hour.
76
Yawns are more contagious among people with closer relationships.
163
Enamel is hardest substance in the human body.
61
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193
It would take about 1,200,000 mosquitoes to fully drain the average human body of blood.
217