Enamel is hardest substance in the human body.
61
Every year your body replaces 98% of your atoms.
119
If you are cold you are more likely to be hungry because you use energy to keep warm.
143
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149
Your thumb is about the same size as your nose.
124
The human brain uses approximately as much energy as a 10 watt light bulb.
120
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
Yawns are more contagious among people with closer relationships.
163