Your thumb is about the same size as your nose.
124
Enamel is hardest substance in the human body.
61
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
It takes about 20 seconds for a red blood cell to circle the whole body.
102
Your body is creating and killing about 2.4 million red blood cells per second.
17
The human brain doesn't stop developing until about 25 years old.
102
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515