Yawns are more contagious among people with closer relationships.
163
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
Enamel is hardest substance in the human body.
61
Your thumb is about the same size as your nose.
124
One human hair can support 3 ounces.
191
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22
Every year your body replaces 98% of your atoms.
119