Dogs can be trained to identify the scent of lung cancer long before symptoms develop.
190
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
It would take about 1,200,000 mosquitoes to fully drain the average human body of blood.
217
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
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
It takes about 20 seconds for a red blood cell to circle the whole body.
102