It takes about 20 seconds for a red blood cell to circle the whole body.
102
The average person's skin weighs twice as much as their brain.
131
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Yawns are more contagious among people with closer relationships.
163
One human hair can support 3 ounces.
191
Chewing gum boosts your brain power.
285
Every year your body replaces 98% of your atoms.
119
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99