The average sperm cell swims at 8 inches per hour.
76
The human brain uses approximately as much energy as a 10 watt light bulb.
120
If your DNA was stretched out it would reach to the moon 6,000 times.
256
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
When you take a step, you are using up to 200 muscles.
886
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
The average person's skin weighs twice as much as their brain.
131