Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
The average person's skin weighs twice as much as their brain.
131
If you are cold you are more likely to be hungry because you use energy to keep warm.
143
Chewing gum boosts your brain power.
285
After age 30, the brain begins to lose about 50,000 neurons per day - shrinking the brain .25% each year.
55
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
Enamel is hardest substance in the human body.
61