How is the skin structured?
A closer look at the struc-ture of the skin reveals three distinct layers:
1. the epidermis，
2. the dermis and the
3. subcutaneous layer.
The dermis is above the subcutaneous layer andessentially comprises elastic fibres, which are interwoven diagonally and horizontally, giving it great strength. The blood vessels end in the dermis, while the sweat and sebaceous glands as well as the hair follicles are also located there.
The basal cell layer is in the epidermis at the transition between it and the dermis. This layer constantly generates new cells, which then move upwards, flatten, become cornified and are eventually sloughed off.
What is Tanning?
Most of us experience sunbathing as something very pleasant. The warmth and relaxation gives us a sense of well-being. But what is actually happening in the skin?
The rays of the sun strike melanin pigments in the epidermis. These are darkened by the UVA rays in the light. The melanin pigments are formed by special cells lying deeper in the skin structure called melanocytes and then move with the surrounding cells to the surface. The darkened pigments absorb part of the sun's rays and thus protect the deeper skin layers.
The UVB range of the sunJs rays penetrates deeper into the skin and acts on the melano-cytes themselves. These are then stimulated to form more pigments: thus creating the basis for a good tan. At the same time, the UVB rays cause the horny layer (the callus) to thicken. This thicker layer contributes towards protecting the skin.
What other effects does the sun have than tanning?
The soothing effect of sunbathing stems not only from the warmth and relaxation experienced but also from the energising effect of bright light; everyone knows the good mood that only a sunny summer's day can bring.
In addition, small doses of UVB promote meta-bolic processes and stimulate the formation of Vitamin D3.
The sun thus gives rise to a wealth of positive effects:
1. a boost in physical vitality
2. the reinforcement of the body’s own defences
3. an improvement in blood flow properties
4. an improvement h oxygen supply to the body’s tissue
5. advantageous mineral metabolism through improved supply of calcium
6. the prevention of bone disease (e.g. osteoporosis, osteomalacia)
Sunburn is one sure sign that the skin has been overexposed and so must be avoided at all costs.
What is sunlight?
Light - and particularly sunlight - is a source of energy without which life is inconceivable. Physics describes light as electromagnetic radiation - like radio waves but on a different frequency. Sunlight comprises a multitude of different frequencies which we can actually see using a prism, j.e. the colours of the rainbow. But the spectrum does not end at red and blue. After red comes infra-red, which we experience as warmth, after blue and violet comes ultra-violet, UV light, which causes skin tanning.
Sunbathing outside or In the solarium - is there a difference?
Sunlight, whether it comes from a wall socket or the sky，is fundamentally the same. There is no such thing as “artificial light” in the sense of it being fundamentally different from sunlight. One great advantage of sunbeds, however, is that the individual components of the spectrum can be precisely adjusted to the needs of the user. In addition, there are no clouds to block out the sun on a sunbed so the dose cam always be accuratelydetermined. It is important to ensure both outdoors and on the sunbed that the skin is not overloaded.
Tanning without burning - how does that work?
The rays of the sun can, in addition to the desired tanning effect，also cause undesirable reddening of the skin, erythema - in its
worse form, sunburn. For one-off sunbathing, the time required for tanning is actually longer than that required for skin reddening.
Despite this, it is also possible to achieve a nice tan, without burning - quite simply by means of regular sunbathing. The reason for this is that the body reduces the preliminary stages of skin reddening relatively quickly, while the tan constantly builds itself up through repeated exposure.
On the sunbed the exact intensity of the UV light is known. Consequently the tanning plan can be adjusted to ensure that the individual stops before burning starts and then that a good tan is built up through repeated exposure.