Yawns are more contagious among people with closer relationships.
163
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
Your body is creating and killing about 2.4 million red blood cells per second.
17
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
Your thumb is about the same size as your nose.
124
Poor eyesight (myopia) is associated with higher IQ.
232
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197