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
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 adult human brain weighs about 3 pounds (1,300-1,400 g).
99
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Dogs can be trained to identify the scent of lung cancer long before symptoms develop.
190