The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
The human brain uses approximately as much energy as a 10 watt light bulb.
120
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
Every year your body replaces 98% of your atoms.
119
The average sperm cell swims at 8 inches per hour.
76
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
The human body contains over a billion miles of DNA.
147