Yawns are more contagious among people with closer relationships.
163
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
One human hair can support 3 ounces.
191
The average sperm cell swims at 8 inches per hour.
76
Our Right Lungs takes more air than our left lung.
194
The human brain uses approximately as much energy as a 10 watt light bulb.
120
Enamel is hardest substance in the human body.
61
Your body is creating and killing about 2.4 million red blood cells per second.
17