There are various theories of why fingers and toes wrinkle in
water. Most biologists suggest that the tough outer layer of skin
made up of dead keratin cells is responsible. Keratin is a protein
found in hair, nails, and the outermost layer of our skin.
Our skin is made up of three layers:
- The subcutaneous tissue is the deepest layer. It contains
fats and connective tissue along with large blood vessels and
nerves.
- The dermis is the middle layer. It contains the blood
vessels, nerves, hair roots, and sweat glands.
- The epidermis is
the topmost layer. It helps to prevent evaporation of water
from the body and to protect the internal
layers from harm.
The epidermis is made up of four layers:
- the stratum corneum
- granular layer
- squamous cell layer
- and basal cell layer
The stratum corneum is the outer layer of our skin - the part
that we can see and feel. This is the layer with the dead keratin
cells.
While a person is in the pool or a bathtub for a long time, the
dead keratin cells absorb water. This absorption causes the surface
area of the skin to swell, but the outer layer is tightly attached
to the living tissue. So, to compensate for the increased surface
area, our skin wrinkles.
So why does this happen to hands and feet and not to other parts
of the body? Because the hands and feet have the thickest layer
of dead keratin cells. Our hands and feet are subjected to a lot
of wear and tear. Imagine if the palm of our hands had skin as
thin as that on our backs. No fun playing basketball with skin
that thin!
For more fascinating facts about the skin see the following Web
sites and further reading sections.
Related
Web Sites |
- About
the Skin - This Web site, from the British Association
of Dermatology, provides all types of information about
the skin, such as the importance of skin and
its role as a barrier, as well as information about
skin
cancer and other diseases.
- Anatomy
of the Skin - This Dermatology Health Guide, from
The University of Maryland Medicine, contains interesting
skin facts and information on skin diseases and conditions.
- What
causes wrinkled fingers? - A discussion about what
causes wrinkled fingers from the Biolab listserv. The
Biolab listserv is an email list for discussion of
issues and information related to teaching college
biology.
- The
Whole Story on Skin - "Created by The Nemours
Foundation's Center for Children's Health Media, Kids
Health provides families with accurate, up-to-date,
and jargon-free health information they can use." The
section on skin provides interesting skin facts, an
illustration of the epidermis, additional articles
about the skin, and related web resources.
- The
World of Skin Care: an on-line reference by Dr. John
Gray, provided by the P&G Skin Care Research Center -
This reference from Procter and Gamble provides information
about the structure,
function, and care of skin as well as information about skin problems and aging.
The information is presented in a book format with a table of contents and index.
|
Further
Reading |
- Brynie,
Faith Hickman. 101 questions about your skin that
got under your skin
until now. Brookfield,
CT, Millbrook Press, c1999. 176 p. (Juvenile).
- Lappe.
Marc. The body's edge: our cultural obsession with
skin. New York, Henry Holt and Company, 1996. 242
p.
-
Robbins, C.R. Skin in the Encyclopedia
of human biology. Edited by Renato Dulbecco.
v. 8. San Diego, Academic Press, c. 1997. p. 39-47.
- Royston,
Angela. Why do I get a sunburn? And other questions
about skin. Chicago, Heinemann Library, 2003. 32
p. (Juvenile).
|
For
more print resources...
Search on "skin," "skin--anatomy," or "dermatology--popular
works"
in the Library of Congress Online
Catalog. |
Diagram
of human skin layers.
From the National Institute of General Medical Sciences Web
site.
From National Weather Service http://www.wrh.noaa.gov/hanford/climo/
elnino/ensoquiz/ensoq3d.htm
From About Faces: the Skin. National Institute of Dental and
Craniofacial Research http://www.nidcr.nih.gov/iyf/skin.html
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