Yawns are more contagious among people with closer relationships.
163
When you take a step, you are using up to 200 muscles.
886
It takes about 20 seconds for a red blood cell to circle the whole body.
102
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
If you are cold you are more likely to be hungry because you use energy to keep warm.
143
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266