Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
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
The average person's skin weighs twice as much as their brain.
131
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
Your thumb is about the same size as your nose.
124
Every year your body replaces 98% of your atoms.
119