Enamel is hardest substance in the human body.
61
The average person's skin weighs twice as much as their brain.
131
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
The human brain doesn't stop developing until about 25 years old.
102
Your thumb is about the same size as your nose.
124
Yawns are more contagious among people with closer relationships.
163