For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
Your body is creating and killing about 2.4 million red blood cells per second.
17
It would take about 1,200,000 mosquitoes to fully drain the average human body of blood.
217
Dogs can be trained to identify the scent of lung cancer long before symptoms develop.
190
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
If your DNA was stretched out it would reach to the moon 6,000 times.
256
There are times when you're walking that the pressure on your feet exceeds your body weight, and when you're running, it can be three or four times your weight.
62