10 Things You Didn’t Know About Skin

1. It’s your body’s largest organ.

• Ooh, what smells like that?  Body odor comes from a second kind of sweat—a fatty secretion produced by the apocrine sweat glands, found mostly around the armpits, genitals and anus.

• Breasts are a modified form of the apocrine sweat gland.

• Fingerprints increase friction and help grip objects. New World monkeys have similar prints on the undersides of their tails, to grasp as they swing from branch to branch.

• There are at least five types of receptors in the skin that respond to pain and to touch.

• White skin appeared 20,000 to 50,000 years ago, as dark-skinned humans migrated to colder climes and lost much of their melanin pigment.

• An average adult’s skin spans 21 square feet, weighs 9 pounds, and contains more than 11 miles of blood vessels.

• The skin releases as much as 3 gallons of sweat a day in hot weather. The areas that don’t sweat are the nail bed, the margins of the lips, the tip of the penis and the eardrums.

• Yummy! The odor is caused by bacteria on the skin eating and digesting those fatty compounds.

 Some people never develop fingerprints at all. Two rare genetic defects, known as Naegeli Syndrome and dermatopathia pigmentosa reticularis, can leave carriers without any identifying ridges on their skin.