Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
The human brain doesn't stop developing until about 25 years old.
102
When you take a step, you are using up to 200 muscles.
886
The human body contains over a billion miles of DNA.
147
Enamel is hardest substance in the human body.
61
There are times when you're walking that the pressure on your feet exceeds your body weight, and when you're running, it can be three or four times your weight.
62
Stress can result in more headaches as a result of the body rerouting blood flow to other parts of the body.
92