Yawns are more contagious among people with closer relationships.
163
When you take a step, you are using up to 200 muscles.
886
The human brain doesn't stop developing until about 25 years old.
102
Your body is creating and killing about 2.4 million red blood cells per second.
17
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
Enamel is hardest substance in the human body.
61
Your heart will pump about 212 million liters in its lifetime.
26
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