Skin has mesodermal cells, pigmentation, or melanin provided by melanocytes, which absorb
some of the potentially dangerous ultraviolet
radiation (UV) in sunlight.
It also contains DNA-repair
enzymes that help reverse
UV damage, and people who lack the genes
for these enzymes suffer high rates of skin cancer. One form
predominantly produced by UV light, malignant melanoma, is particularly
invasive, causing it to spread
quickly, and can often be deadly. Human skin pigmentation varies among
populations in a striking manner. This has led to the classification of
people(s) on the basis of skin color.
The skin is the largest organ in the human body.
For the average adult human, the skin has a surface area of between 1.5-2.0
square metres (16.1-21.5 sq ft.), most of it is between 2–3 mm
(0.10 inch) thick. The average square inch (6.5 cm²) of skin holds
650 sweat glands, 20 blood vessels, 60,000 melanocytes, and more than 1,000
nerve endings.
Skin performs the following functions:
1. Protection: an anatomical barrier from pathogens
and damage between the internal and external environment in bodily defense; Langerhans cells in the
skin are part of the adaptive
immune system.[3][4]
2. Sensation: contains a variety of nerve endings
that react to heat and cold,
touch, pressure, vibration, and tissue injury; see somatosensory
system and haptics.
3. Heat regulation: the skin contains a blood supply far
greater than its requirements which allows precise control of energy loss by
radiation, convection and conduction. Dilated blood vessels increase perfusion
and heatloss, while constricted vessels greatly reduce cutaneous blood flow and
conserve heat.
4. Control of evaporation: the skin provides a relatively dry and
semi-impermeable barrier to fluid loss.[4] Loss of this function contributes to
the massive fluid loss in burns.
5. Aesthetics and communication: others see our skin and can assess our
mood, physical state and attractiveness.
6. Storage and synthesis: acts as a storage center for lipids and
water, as well as a means of synthesis of vitamin D by action of UV on certain parts of the
skin.
7. Excretion: sweat contains urea, however its
concentration is 1/130th that of urine,
hence excretion by sweating is
at most a secondary function to temperature regulation.
8. Absorption: the cells comprising the outermost
0.25–0.40 mm of the skin are "almost exclusively supplied by external
oxygen", although the "contribution to total respiration is
negligible".[8] In addition, medicine can be administered through the
skin, by ointments or by means of adhesive patch, such as the nicotine patch or iontophoresis. The skin is
an important site of transport in many other organisms.
9. Water resistance: The skin acts as a water resistant barrier
so essential nutrients aren't washed out of the body.
The first step towards
beautiful skin is working out what your skin type is. This is necessary so
that you can work out how to care for your skin, and what products you should
use. Below are the features of the 5 main skin types which you can
compare to your own skin type. Once you have decided what type your skin is you
can find out what the best way is to look after your skin.
Which of these do you
think is the closest match to your skin?
Normal
Skin Type
Normal skin does not feel dry
or oily.
Pores are visible but not large or clogged.
After a wash it feels
smooth and comfortable.
At midday it still looks fresh and clean.
Only
occasionally break out in spots.
Caring for Normal Skin
Type:
To care for normal skin you
should start with a gentle foaming facial wash. Massaging it into your face
will give you a rosy complexion. Cool your skin with a refreshing toner. to
finish dot moisturiser onto your skin and massage it with your fingers in light
upward strokes.
Dry Skin Type
Dry skin has a thin and
papery texture.
It feels dry to touch.
The pores are very fine.
After a wash it
feels tight, as though it is too small for the face.
By midday flaky patches
appear.
Hardly ever break out in spots.
Caring for Dry Skin Type:
For dry skin use a creamy
cleanser to melt away dirt. Leave it on your skin before sweeping it away with
cotton wool. Splash cold water onto your face to clean and refresh your skin.
Use a thick cream moisturiser to seal in as much moisture as possible.
Oily Skin Type
Oily skin feels very
greasy.
The texture is often very thick and coarse.
There are large, visible
pores.
After a wash it feels fine.
By midday it looks shiny.
Often break out in
spots.
Caring for Oily Skin Type:
To care for oily skin you
should start with a gentle, foaming facial wash. This will remove dirt and oil
without stripping away moisture. Soak cotton wool in a gentle astringent lotion
and sweep it over your skin to refresh and cool it. Even oily skin needs a
moisturiser, but chose a light, watery fluid; this will be enough for your
skin. Allow the moisturiser to sink in and then absorb the excess with a tissue
to prevent shine.
Combination
Skin Type
Combination skin is normal
with a few dry patches and a few oily patches.
Dryness is usually on the
cheeks.
Oiliness is usually on the T-zone.
After a wash some areas feel dry and
some smooth.
By the midday the T-zone is shiny.
Often break out in spots in the
T-zone.
Most women have combination skin.
Caring for Combination
Skin Type:
If you have combination skin
use a foaming facial wash in the mornings to cleanse your skin. This will keep
the oily areas clean to prevent blackheads. In the evening use a cream cleanser
to soothe your dry areas. This will keep a balance between excess dryness and
excess oiliness. Use a strong astringent for your oily areas and a mild skin
freshener for the dry areas. This is not an expensive option, as you will only
need a little of each. Use moisturiser on your whole face, but make sure you
concentrate on your drier areas.
Sensitive
Skin Type
Sensitive skin can be easily
irritated.
Typical reactions are itching, burning, chafing and stinging.
After
a wash a wash it feels dry and itchy in places.
By midday there are flaky
patches and some redness.
Occasionally break out in spots.
Caring for Sensitive Skin
Type:
If you have sensitive skin do not use
facial washes or soap; instead use a light, hypoallergenic cleansing lotion.
Use a moisturiser to strengthen your skin and provide a barrier against
irritants. Make sure you use an unperfumed moisturiser so as not to irritate
your skin.
So, do you want to know what type is your skin???