The human sigh acts as a physiological reset button.
23
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.
269
If your DNA was stretched out it would reach to the moon 6,000 times.
256
The average sperm cell swims at 8 inches per hour.
76
All humans have the ability to see ultraviolet light, but it is passively filtered out by the eye's lens. People who undergo surgery to remove the lens can detect ultraviolet light.
22
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