Dogs can be trained to identify the scent of lung cancer long before symptoms develop.
190
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
It takes about 20 seconds for a red blood cell to circle the whole body.
102
One human hair can support 3 ounces.
191
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 largest cell in the human body is the female egg and the smallest is the male sperm.
682
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515