Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
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
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
The human brain uses approximately as much energy as a 10 watt light bulb.
120
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
There are times when you're walking that the pressure on your feet exceeds your body weight, and when you're running, it can be three or four times your weight.
62
It would take about 1,200,000 mosquitoes to fully drain the average human body of blood.
217
Your body is creating and killing about 2.4 million red blood cells per second.
17