Your thumb is about the same size as your nose.
124
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
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
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
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
Women have about four times as many foot problems as men; lifelong patterns of wearing high heels often are the culprit.
111
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193