When you take a step, you are using up to 200 muscles.
886
Enamel is hardest substance in the human body.
61
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
Yawns are more contagious among people with closer relationships.
163
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22
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