Yawns are more contagious among people with closer relationships.
163
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
The average sperm cell swims at 8 inches per hour.
76
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
All the chemicals in a human body combined are worth about 6.25 euro (if sold separately).
266
Most of us have microscopic, worm like mites named Demodex that live in our eyelashes and have claws and a mouth.
-137
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Every year your body replaces 98% of your atoms.
119