Yawns are more contagious among people with closer relationships.
163
An average heart beats 100,000 times a day, pumping some 2,000 gallons of blood through its chambers. Over a 70-year life span, that adds up to more than 2.5 billion heartbeats.
73
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
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
The human brain is very soft, having a consistency similar to soft gelatin or firm tofu.
13
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