For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
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
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
The human brain uses approximately as much energy as a 10 watt light bulb.
120
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
Enamel is hardest substance in the human body.
61
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99