The human brain doesn't stop developing until about 25 years old.
102
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
The average sperm cell swims at 8 inches per hour.
76
The human body contains over a billion miles of DNA.
147
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
Your body is creating and killing about 2.4 million red blood cells per second.
17
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18