Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Enamel is hardest substance in the human body.
61
When you get goosebumps and your hair stands, the hair helps to trap air, making you feel warmer by keeping in your body heat.
46
When you take a step, you are using up to 200 muscles.
886
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22
The average person's skin weighs twice as much as their brain.
131
It would take about 1,200,000 mosquitoes to fully drain the average human body of blood.
217