Feeds

Why do your hands turn white when you wash the dishes?

Shrivelling skin

The smart choice: opportunity from uncertainty

Also in this week's column:

Why do your hands turn white when you wash the dishes?

Asked by Erin West of Oyster Bay, New South Wales, Australia</small

Human skin is made up of three layers. The outer layer is called the epidermis. "Epidermis" is from the Greek words "epi" meaning "on" and "derma" meaning "skin". It is a tough protective layer that contains melanin. Melanin both protects skin from the sun and gives skin its pigmentation.

Under the epidermis is the second layer called the dermis. It contains nerve endings, sweat glands, oil glands, and hair follicles.

Beneath the dermis is the third layer composed of subcutaneous fat. "Subcutaneous" means "under the skin".

Human skin is quite different in thickness in different areas of the body. The skin on the palms, fingers, soles, and toes is somewhat thicker than in other places. Skin colour becomes white from the opaqueness produced by the increased water content of the skin. Skin that has been submerged under water, such as your hands when washing dishes, appears wrinkled and shriveled up too.

Most people believe that this appearance is due to the skin shrinking. Quite the opposite is the case. The skin is actually expanding from the absorption of water.

Water is absorbed by skin immersed in water through the process of osmosis. This is because the internal body fluids of humans are more concentrated than in fresh water. Skin whitening, wrinkling and shriveling up appear because these areas of thicker skin expand as they become saturated.

Skin elsewhere on the body soaks up water after prolonged immersion. However, because this skin is thinner, there is more room for moisture, and the whitening, wrinkling, and shriveling up takes longer to appear.

Interestingly, the whitening, wrinkling, and shriveling do not occur from ocean salt water. This is because sea water is very similar to the fluids in the human body and osmosis does not take place.

Interesting facts

  • The skin of the average adult has a surface area of between 1.5 and 2.0 square meters. Most of this is between 2mm and 3mm thick.
  • The average square inch of skin holds 650 sweat glands, 20 blood vessels, 60,000 melanocytes, and more than 1000 nerve endings.

Stephen Juan, Ph.D. is an anthropologist at the University of Sydney. Email your Odd Body questions to s.juan@edfac.usyd.edu.au

Eight steps to building an HP BladeSystem

More from The Register

next story
Malaysian Airlines flight MH17 claimed lives of HIV/AIDS cure scientists
Researchers, advocates, health workers among those on shot-down plane
Mwa-ha-ha-ha! Eccentric billionaire Musk gets his PRIVATE SPACEPORT
In the Lone Star State, perhaps appropriately enough
The Sun took a day off last week and made NO sunspots
Someone needs to get that lazy star cooking again before things get cold around here
All those new '5G standards'? Here's the science they rely on
Radio professor tells us how wireless will get faster in the real world
Diary note: Pluto's close-up is a year from … now!
New Horizons is less than a year from the dwarf planet
Boffins discuss AI space program at hush-hush IARPA confab
IBM, MIT, plenty of others invited to fill Uncle Sam's spy toolchest, but where's Google?
prev story

Whitepapers

Seven Steps to Software Security
Seven practical steps you can begin to take today to secure your applications and prevent the damages a successful cyber-attack can cause.
Consolidation: The Foundation for IT Business Transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.
Designing a Defense for Mobile Applications
Learn about the various considerations for defending mobile applications - from the application architecture itself to the myriad testing technologies.
Build a business case: developing custom apps
Learn how to maximize the value of custom applications by accelerating and simplifying their development.
Consolidation: the foundation for IT and business transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.