Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193
Your body is creating and killing about 2.4 million red blood cells per second.
17
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22
Every year your body replaces 98% of your atoms.
119
After age 30, the brain begins to lose about 50,000 neurons per day - shrinking the brain .25% each year.
55
The average sperm cell swims at 8 inches per hour.
76