For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
The average sperm cell swims at 8 inches per hour.
76
It would take about 1,200,000 mosquitoes to fully drain the average human body of blood.
217
The human body contains over a billion miles of DNA.
147
Yawns are more contagious among people with closer relationships.
163
After age 30, the brain begins to lose about 50,000 neurons per day - shrinking the brain .25% each year.
55
It takes about 20 seconds for a red blood cell to circle the whole body.
102