The average person's skin weighs twice as much as their brain.
131
It takes about 20 seconds for a red blood cell to circle the whole body.
102
An average heart beats 100,000 times a day, pumping some 2,000 gallons of blood through its chambers. Over a 70-year life span, that adds up to more than 2.5 billion heartbeats.
73
Enamel is hardest substance in the human body.
61
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
Poor eyesight (myopia) is associated with higher IQ.
232
It would take about 1,200,000 mosquitoes to fully drain the average human body of blood.
217
Your thumb is about the same size as your nose.
124