Enamel is hardest substance in the human body.
61
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149
Yawns are more contagious among people with closer relationships.
163
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
The average sperm cell swims at 8 inches per hour.
76
Chewing gum boosts your brain power.
285
It takes about 20 seconds for a red blood cell to circle the whole body.
102
If you are cold you are more likely to be hungry because you use energy to keep warm.
143