All about your skin

There's about eighteen square feet of skin on your body. it's the paper bag that keeps you intact! So, it's an important working bodily organ as well as a source of beauty. If you cut a section through your skin you'd find that it's composed of closely-connected layers. The three main layers are: the epidermis (outer covering), the dermis (which lies just below the epidermis) and the sub dermis (below the dermis and a part of the subcutaneous tissue).

The epidermis itself has five distinct layers: the stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum and stratum germinativum. The dermis contains the sebaceous glands which produce sebum (or body oil), sweat glands and hair follicles plus the vital nerve endings. Cosmetics can penetrate only the epidermis; otherwise they are classified as drugs. However, recent research has shown that cosmetics and face creams can create more dramatic changes than was realized a few years ago - but more of that later.

Here's a blow-by-blow account of the function and structure of the five layers of the epidermis:

Stratum corneum (or horny later) this is the outside covering composed of seven different layers of cells, each one thin and flat. These cells have lost water on the way up from the stratum germinativum; by the time they reach the surface they contain about 15 per cent water, which gives the skin its bloom and soft appearance.

Stratum lucidum (or clear layer) this consists of three separate layers of clear cells. These cells are waiting to journey upwards to the stratum corneum.

Stratum granulosum (or granular later) under a microscope you'd see that this layer is only one or two cells thick and has a granular appearance, since each of the cells is filled with little granules.

Stratum spinosum (or spiny layer) this consists of about fifteen layers of cells which have a spiny appearance. Little projections fit together so that one cell hooks up with the next. It's vital to keep these cells hooked up, otherwise your skin would drop off! In fact, at the ripe old age of seventy or so, you start losing the little projections between the cells and your skin starts "slipping".

Stratum germinativum (or germinating layer) this is the only cell layer that's actually alive: each cell in this layer divides and journeys upwards through the other four layers to arrive finally on the skin's surface. This constant renewal process takes about seventeen to twenty-three days.

How can you keep your skin looking good? First, it's vital to realize water is the main ingredient of a soft, youthful-looking skin. Unfortunately, central heating, the elements and the ageing process all conspire to rob the skin of this vital moisture. There are many creams on the market which help prevent moisture-loss by adding a fine layer of protective oily film over the skin. These "occlusive" creams can certainly help when you're up against wind, rain and day-to-day skin drying villains. They also provide a good base for make-up and powder. However, the creams don't soften the skin. its water that does that! A recent development in skin creams on the continent has produced a molecular structure which actually regulates the water-content of the skin, according to the conditions experienced. It's a net-like structure, very sparingly applied, which really helps that water-loss problem. These creams (Vichy's equalia, for example) are now widely available from chemists here, too.

Can diet help? Doctors are divided about the role diet plays in skin health. However it's a fact that the skin is made from protein and needs protein to be renewed. If you eat insufficient protein (or incomplete proteins which do not contain all the amino-acids needed to process the protein), your muscles will lose tone, your skin will become muddy-looking and dry, and wrinkles will appear. It's widely assumed that the Western diet is packed with protein, but this is not always the care - you may, for instance, have trimmed your housekeeping budget by cutting down the amount of meat and fish you eat. Remember that there are other good sources of proteins: brewer's yeast, nuts, soya beans, milk, liver, and kidneys. As you get older, you should aim to check that your skin is getting its fair share - at least 100 grams a day. If you are a vegetarian, you need to be extra careful about your protein intake. Other nutrients which indirectly but diligently, work for the health of your skin are: vitamin B complex (yeast, wheatgerm, liver, kidneys), Vitamin C (citrus fruits). Baddies are booze (which dilates blood vessels and dehydrates the whole body, including the skin), fried foods and sugary foods.

What about open pores and acne? Pores (which are really hair follicles, see above) are really tiny tunnels through which sweat and sebum are constantly pumped. The sebaceous glands in the dermis are about three to four times as large in the "T-zone" of the face- across the forehead, down the nose, across the upper lip and on the chin. So, these areas tend to be oilier. No lotion will "close" pores although some manufacturers claim that their products will do so. In fact, many 'pore tighteners' simply irritate the pores, setting up a swelling reaction which gives a temporary appearance of a smoother skin. However, the pore opening will often take on a 'funnel' appearance where deposits of sebum and debris have gathered around the opening; the funnel is wider at the top, narrower at the bottom. If the face is scrupulously cleaned to remove the debris, the Skin is highly complicated structure. This diagram shows:

a.                  hair shaft

b.                 stratum corneum

c.                 stratum lucidum

d.                 stratum granulosum

e.                  stratum spinosum

f.                   stratum germinativum

g.                 sebaceous gland

h.                 blood vessels

i.                    papilla

j.                    sweat gland and duct

k.                 fatty tissue 

You can see that the top five layers of your skin are very busy a constantly changing "procession" of cells rising to the top and undergoing a fascinating conversion process on the way up. What happens is that the cells lose water on the journey, converting their juicy protoplasm to keratin protein. This is the same kind of protein that makes up hair and nails, but in the skin it's much softer, retaining that 15 per cent of water I mentioned earlier, and with a different molecular structure. a much weaker "hooked-together" from than the harder type of keratin.

Meanwhile, down in the dermis, there's a lot going on too. As already mentioned, this layer contains a veritable power-house of working prats from the sebaceous glands to the nerve endings that give your skin its "feelings". Here, the sebaceous glands pump sebum into the hair follicles or "pores" of the skin to produce a protective and softening covering on top of the horny layer. This pumping process is controlled by hormonal factors which, in turn, are influenced by bodily rhythms and developments like puberty, menstruation and the menopause.

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