Yawns are more contagious among people with closer relationships.
163
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
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
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
It would take about 1,200,000 mosquitoes to fully drain the average human body of blood.
217
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197