Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Every year your body replaces 98% of your atoms.
119
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193
The human brain uses approximately as much energy as a 10 watt light bulb.
120
An Indian man known as "Snake Manu" can put small snakes, including deadly cobras, into his mouth and pass them out through his nose.
59
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
The largest cell in the human body is the female egg and the smallest is the male sperm.
682