Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Most of us have microscopic, worm like mites named Demodex that live in our eyelashes and have claws and a mouth.
-137
Enamel is hardest substance in the human body.
61
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
The human brain uses approximately as much energy as a 10 watt light bulb.
120
When you take a step, you are using up to 200 muscles.
886
Your heart will pump about 212 million liters in its lifetime.
26
The human brain doesn't stop developing until about 25 years old.
102