Your body is creating and killing about 2.4 million red blood cells per second.
17
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
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
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
It would take about 1,200,000 mosquitoes to fully drain the average human body of blood.
217
The human brain doesn't stop developing until about 25 years old.
102
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 human brain is very soft, having a consistency similar to soft gelatin or firm tofu.
13