Enamel is hardest substance in the human body.
61
Yawns are more contagious among people with closer relationships.
163
Your thumb is about the same size as your nose.
124
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149
The human brain uses approximately as much energy as a 10 watt light bulb.
120
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
Every year your body replaces 98% of your atoms.
119
Poor eyesight (myopia) is associated with higher IQ.
232