Enamel is hardest substance in the human body.
61
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
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
The average person's skin weighs twice as much as their brain.
131
After age 30, the brain begins to lose about 50,000 neurons per day - shrinking the brain .25% each year.
55
Every year your body replaces 98% of your atoms.
119