The human body contains over a billion miles of DNA.
147
The human brain doesn't stop developing until about 25 years old.
102
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
The average sperm cell swims at 8 inches per hour.
76
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
It takes about 20 seconds for a red blood cell to circle the whole body.
102
Yawns are more contagious among people with closer relationships.
163
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18