Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
The human brain uses approximately as much energy as a 10 watt light bulb.
120
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
Stress can result in more headaches as a result of the body rerouting blood flow to other parts of the body.
92
Your body is creating and killing about 2.4 million red blood cells per second.
17