It takes about 20 seconds for a red blood cell to circle the whole body.
102
When you get goosebumps and your hair stands, the hair helps to trap air, making you feel warmer by keeping in your body heat.
46
The average person's skin weighs twice as much as their brain.
131
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
Your body is creating and killing about 2.4 million red blood cells per second.
17
Your thumb is about the same size as your nose.
124
Enamel is hardest substance in the human body.
61