Yawns are more contagious among people with closer relationships.
163
Enamel is hardest substance in the human body.
61
Our Right Lungs takes more air than our left lung.
194
The human brain doesn't stop developing until about 25 years old.
102
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.
144
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515