Enamel is hardest substance in the human body.
61
It takes about 20 seconds for a red blood cell to circle the whole body.
102
Your thumb is about the same size as your nose.
124
Yawns are more contagious among people with closer relationships.
163
Your body is creating and killing about 2.4 million red blood cells per second.
17
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
It would take about 1,200,000 mosquitoes to fully drain the average human body of blood.
217
An Indian man known as "Snake Manu" can put small snakes, including deadly cobras, into his mouth and pass them out through his nose.
59