Your body is creating and killing about 2.4 million red blood cells per second.
17
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
Your heart will pump about 212 million liters in its lifetime.
26
Your thumb is about the same size as your nose.
124
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
It takes about 20 seconds for a red blood cell to circle the whole body.
102
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