Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Your body is creating and killing about 2.4 million red blood cells per second.
17
Yawns are more contagious among people with closer relationships.
163
Our Right Lungs takes more air than our left lung.
194
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
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
One human hair can support 3 ounces.
191
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266