The average sperm cell swims at 8 inches per hour.
76
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
If you are cold you are more likely to be hungry because you use energy to keep warm.
143
It takes about 20 seconds for a red blood cell to circle the whole body.
102
The human brain doesn't stop developing until about 25 years old.
102
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22
When you take a step, you are using up to 200 muscles.
886