The average sperm cell swims at 8 inches per hour.
76
Your thumb is about the same size as your nose.
124
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
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18