Enjoy:
It takes about six months for a toenail, and three months for a fingernail, to grow from the base to the tip.
The pop you get when you crack your knuckles is a bubble of gas escaping from the joints between finger bones.
A pack-a-day smoker will lose approximately two teeth every ten years.
Beards are the fastest growing hairs on the human body. If the average man never trimmed his beard, it would grow nearly 30 feet (9m) long in his lifetime.
The hairs on your arms are programmed to stop growing every couple of months, so they stay short. But the hair follicles on your head are programmed to grow for years at a time, so this type of hair can grow very long.
An average human scalp has 100,000 hairs.
Every human being has a unique smell shared by no other human being.
Humans are the only primates that don't have dark pigment in the palms of their hands.
If locked in an airtight room, you will die by breathing your own carbon dioxide, which is poisonous, rather than from lack of oxygen.
