Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
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 human body contains over a billion miles of DNA.
147
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22
Your heart will pump about 212 million liters in its lifetime.
26