Enamel is hardest substance in the human body.
61
Dogs can be trained to identify the scent of lung cancer long before symptoms develop.
190
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
It takes about 20 seconds for a red blood cell to circle the whole body.
102
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 uses approximately as much energy as a 10 watt light bulb.
120
It would take about 1,200,000 mosquitoes to fully drain the average human body of blood.
217
Poor eyesight (myopia) is associated with higher IQ.
232