Yawns are more contagious among people with closer relationships.
163
One human hair can support 3 ounces.
191
The human brain is very soft, having a consistency similar to soft gelatin or firm tofu.
13
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
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
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
Your heart will pump about 212 million liters in its lifetime.
26