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Skin Health
By peace | November 27, 2006
The skin reflects your general health and social behaviour. Situations which effect your health can have an important effect on your skin, for example cigarette smoking causes ageing and wrinkling of the skin with time.
If your skin changes suddenly and with no apparent reason it may be a sign of ill health, e.g. the sudden onset of dry skin with coarse hair and weight gain may mean your thyroid gland is underactive.
Keeping the skin clean is important to prevent infections and odours but excess washing can particularly in people with a tendency to dry skin already, cause loss of oil in the outer layers of the skin and provoke dermatitis. Similarly, chemicals such as petrol, white spirit and detergents can cause dry and damaged skin leading to hand dermatitis. This is a large cause of illness related to occupation; people particularly at risk are those who have their hands in and out of water a lot, such as hairdressers, nurses, mechanics etc. The young and the elderly have more sensitive skin because their barrier is less well formed. People who have had eczema, asthma or hay fever as children are more prone to these problems in adult life.
The major cause of ageing of our skin is ultraviolet light. Ultraviolet causes pigmentation changes e.g. liver spots or sunspots, broken blood vessels, thinning of the dermis and wrinkling of the skin. In order to prevent this, protection of the skin against ultraviolet light is required. Certain skin types are more susceptible to these effects. Most at risk are those with fair skin that burns easily.
Skin Colour
The colour of skin depends primarily on a pigment called melanin. It is also influenced by the blood flow through the skin. Melanin is a pigment produced by special cells called melanocytes that manufacture packets of melanin called melanosomes and transfer them to the skin cells of the epidermis the keratinocytes.
Melanin pigmentation in humans is of two types. The constitutive colour is that which is genetically determined without the effect of sunshine. The other is inducible skin colour or tan as a consequence of sun exposure. Other factors can darken skin, some hormones e.g. in pregnancy can make the skin darken and some parts of the body are darker than others. In white people the darkest area is the upper thigh and the lower back is the lightest. In black people the abdomen is the darkest.
Melanocytes are found throughout the skin. There are roughly 2×109 melanocytes in the skin of an average person. The number of melanocytes in the skin is the same in all races. The difference in colour between Caucasoid, Mangoloid and Negroid skin is due to the number and arrangement of the melanosomes in the keratinocyte.
Melanin helps protect the skin against the effects of ultraviolet light, and tanning of the skin on sun exposure acts to increase that protection.
The superior sun protection of the black skin is therefore not due to more melanocytes but more melanosomes within the epidermis. Each individual should know how well their skin tans and how easily it burns because this is related to your risk of skin cancer from sunshine.
Topics: All Posts, Man's health, Woman's Health | 1 Comment »
January 25th, 2008 at 2:02 pm
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