It takes about 20 seconds for a red blood cell to circle the whole body.
102
The human brain doesn't stop developing until about 25 years old.
102
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
Enamel is hardest substance in the human body.
61
When you take a step, you are using up to 200 muscles.
886
It would take about 1,200,000 mosquitoes to fully drain the average human body of blood.
217
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22