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
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
After age 30, the brain begins to lose about 50,000 neurons per day - shrinking the brain .25% each year.
55
Stress can result in more headaches as a result of the body rerouting blood flow to other parts of the body.
92
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149
Dogs can be trained to identify the scent of lung cancer long before symptoms develop.
190
The average sperm cell swims at 8 inches per hour.
76