The average sperm cell swims at 8 inches per hour.
76
Enamel is hardest substance in the human body.
61
Every year your body replaces 98% of your atoms.
119
The average person's skin weighs twice as much as their brain.
131
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197