Enamel is hardest substance in the human body.
61
An average heart beats 100,000 times a day, pumping some 2,000 gallons of blood through its chambers. Over a 70-year life span, that adds up to more than 2.5 billion heartbeats.
73
If you are cold you are more likely to be hungry because you use energy to keep warm.
143
When you get goosebumps and your hair stands, the hair helps to trap air, making you feel warmer by keeping in your body heat.
46
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
The human body contains over a billion miles of DNA.
147
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193