Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
It takes about 20 seconds for a red blood cell to circle the whole body.
102
Poor eyesight (myopia) is associated with higher IQ.
232
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
Stress can result in more headaches as a result of the body rerouting blood flow to other parts of the body.
92
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
Chewing gum boosts your brain power.
285
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193