PHYSIOLOGY and PATHOLOGY of the SKIN
WHAT IS THE SKIN?
The skin is the biggest organ in the body with many functions. The skin has one overall function – to protect layers and organs of the body against sun, bacteria and dehydration. The skin has multiple layers and renews itself continuously. The surface of the skin peels and replaces new cells continuously through its renewal process (Every 28 days). The skin heals very effectively and there will be no noticeable damage on for a long time. As you get older a lot of body parts that are responsible for maintaining the skin become inactive, denying the skin not get the required nutrients that are needed. Therefore it is important that you provide the skin with extra nutrients, to take care of it.
To provide the best skin care and to be sure that definite results are obtained with the skin care routine, it is important that every therapist knows and understands the basic combination of the skin.
- It covers and protects internal organs.
- It regulates and controls the temperature of the body.
- It serves as a protection against damaging environmental factors (e.g. heavy weather conditions).
- It helps to get rid of impurities.
- It fights infections and maintains the acid mantle.
- It prevents damaging radiation from entering the body – forming melanin layer.
- It prevents bacteria from entering the body.
- It rinses the body through excretion (e.g. perspiration).
- It prevents dehydration.
- It keeps the body in proportion during moving.
- It serves as an organ of touch for feeling.
- The skin differs in thickness over the body. It is thinner and more sensitive on the face, and is thicker and stronger on the hands and feet.
- The acid mantle is responsible for protection.
- As a sense it informs the body of pressure, temperature, touch and pain.
- It is composed of million of cells, blood and lymph, and nerve channels, a lot of pores, hair follicles, sweat and sebum glands.
The skin has 3 layers:
The epidermis is composed of dead, horny cells. The thickness differs everywhere. The underlying part of the epidermis cells divide continuously allowing the cells to move upwards, where it peels. A chemical change happens on the surface of the skin which changes the cells into a hard protein layer, namely keratin. The horny layer consists of a number of dead cells that lie on top of each other. They are spaced so that it provides the skin with a smooth appearance. Outside factors play a role and makes cells uneven to give skin a rough texture. This is where skincare plays a role. Exfoliation rids the skin of dead cells and stimulates the deeper layers to produce more cells. The life span of a cell is approximately 3 – 4 weeks from forming in the deepest layer to reaching the surface of the skin. This cycle takes longer as the skin gets older. Damage takes longer to heal and the skin loses its young complexion and freshness. Moisturisers serve as a substitute for your natural moisturising system.
The deepest layer of the epidermis produces melanin cells that are responsible for the colour of the skin. The distribution and condition of the cells plays an important role in the colour of the skin. The possibility of the melanin cells to absorb non dangerous UV rays protects the skin against sunburn. When cells are exposed to the sun, they produce more melanin.
Functions and characteristics of the horny layer.
- Protect against dehydration.
- Composed of the acid mantle.
- Makes the skins pH 5.5.
- Cells are spaced like roof tiles that gives the skin the rough texture.
Functions and characteristics of the melanin layer.
- Responsible for skin colour.
- Genes determine the spacing.
- Cells are stimulated by non dangerous UV rays.
- A light skin colour means the cells are wide spaced.
- A dark skin colour means the cells are spaced close together.
The Dermis composes of different cells. It is where cell renewal and cell growth takes place. The Dermis is made up of cell tissue, collagen and elastin. This tissue gives the skin its elasticity.
Medical research shows that this tissue causes ageing of the skin. Factors such as diets, too much sun exposure and sickness causes low water content of this layer. If the dermis layer is not protected, cell growth can not take place.
Functions and characteristics of the dermis
- Composed out of two main components – collagen and elastin.
- Collagen is for the firmness of the skin.
- Elastin is for the elasticity and stretch ability of the skin.
- Fits underneath the epidermis like a puzzle.
- Rich in blood vessels that provide the cells with oxygen and nutrients.
- Rich in lymph vessels that removes impurities.
- Houses the sweat and sebum glands.
- Houses the Erector Pilli muscle that tightens up the pores.
The Hypodermis is the deepest layer of the skin. Blood vessels, lymph vessels and nerve channels get distributed from here to the dermis. The nutrients that are responsible for cell growth get distributed to the rest of the body through this layer. The hypodermis is further composed of tissue that protects the skin from extreme temperature changes. It also protects the body’s internal organs against shock and heavy pressure.
Functions and characteristics of the hypodermis
- It is the deepest layer of the skin.
- Protects and covers the lymph, blood and nerve channels.
- Keeps the body warm and serves as an isolator.
- Serves as storage for energy.
- Separates the dermis from the muscles so that the body can move independently.
- Cell growth and healing takes place in this layer.
Even though hereditary factors, hormones, lifestyle and environmental factors have an influence on the condition of the skin, it can be maintained by protecting it. The skin is conditioned by constant supply of moisture and nutrients to different cells. Environmental factors and hormone changes like menstruation, pregnancy, menopause and contraceptive pills and injections can influence the skin’s sebum and moisture balance. As soon as moisture gets extracted (eg. By the Sun, wind, air conditioner, soaps, cleansing toners) the sebum glands gets activated. The amount of sebum excreted by the skin, determines the moisture balance of the skin. It prevents that too much moisture evaporates from the skin. This moisture system of the skin can often get damaged. If too much moisture is extracted from the skin, the deepest layers will be left dry and dehydrated. It is a natural reaction for the skin to stay moisturised.
Nothing on the surface of the skin ever stays the same. It makes it difficult to categorise the skin type, because the skin changes from day to day and season to season. Everyone has a skin type that gets dryer the older you get.
Product houses spend an enormous amount of money on research on the ingredients that can fight against the natural imbalance of the skin and the effect of the surrounding conditions.
CLASSIFICATION OF SKIN TYPES
Normal Skin and/or healthy skin
- Looks healthy.
- Looks moisturized.
- Feels smooth and soft.
- Fine texture.
- Composed of an acid mantle that is anti bacterial.
- Sebum spread evenly over the skin.
- The surface of the skin has no marks.
- Even pore sized.
- Healthy colour.
- The texture of the skin in fine and smooth.
- It has a relative short life time as a result of damaging outside factors that has an effect on the skin.
- Fine texture.
- Dry and tight feeling because of sebum and moisture shortage.
- Surface of the skin can have fine lines and wrinkles form as a result of dry atmosphere and surrounding conditions.
- No shine or greasiness present on skin.
- Mat appearance.
- Flakiness can be present.
- Can appear thin and sometimes red.
- Milia can be visible.
- Oiliness and shininess on surface of skin can be present.
- Medium to rough texture.
- Blackheads, Whiteheads and enlarged pores visible on skin.
- Oiliness mostly on nose, chin and forehead, because there’s more sebum glands on this area.
- Even though oily, the skin can appear to be dry due to moisture shortage.
- Most common skin type during puberty which can last into the middle age.
- Oiliness mostly on t-panel (middle of the face).
- T-panel is oily while the cheek and eye areas are dryer.
- Enlarged pores, blackheads and blockages are caused by the oiliness.
- In other words, the t-panel has a water shortage and the cheek areas have a oil shortage
- Very red appearance
- Broken veins on the surface of the skin. Veins can become blue as a result of a lack of oxygen or because the skin is thin and the veins which lie just beneath the surface of the skin, are visible.
- Skin burns easily with certain products, especially products witch contains perfume, alcohol or preservatives.
- Loose skin can appear on the surface of the skin as a result of tissue damage.
- The skin must be treated carefully - no toners, exfoliators or drying masks may be used.
- Hayfever, asthma and allergies causes the skin to be sensitive.
- Clients with this skin type are advised not to be exposed to extreme weather e.g. extreme sun and wind.
- Can be a normal, oily, dry, combination or aged skin.
- If skin is pressed upwards, criss-cross lines will be visible.
- Water/ moisture content is low.
- Caused by extreme temperature.
- Dehydration is a problem which occurs with most skin types – people’s immediate reaction is to get rid of the “dryness”. At the same time when the skin excretes oil - The immediate reaction is to use an “oil” product while there is only a moisture shortage. Treatment with oil can result in more oiliness. Use a moisturising cream.
- When the Ph balance (acid level) and the lipid balance (oil and moisture balance) is disturbed, oily T-panels are present.
- The cheek areas are at the same time oily. Strong alkaline products like soaps are then responsible for the condition.
- Is present at combination and oily skin types.
- Appears to be dry.
- Rough texture.
- Big build up of keratinised cells.
- Small pimples can be felt on the skin, but not seen.
Premature ageing skin
- Sun damage is always visible.
- Scars, macules, keratosis and choasma may appear.
- Wrinkles appear.
- Thin dermis – the sun is a huge factor in damaging the collagen and elastin vessels. Skin starts “hanging”. Stress, smoking, wrong diet and bad sleeping habits is the cause of this. Strengthen the skin with gamma lanoline acid.
- Elasticity and muscle tone will be poor.
Pigmentation and the causes
Pigmentation is caused due to exposure to damaging UV rays of the sun and due to stimulation of melanin. It is a reaction between UV rays and pigments of the skin. This reaction shows on the skin in the form of blemishes. Pigmentation and skin damage is also due to exposure to fluorescent light, microwaves and computers.
- -Forms in the epidermis layer.
- -Form when melanin cells are stimulated by non damaging radiation.
- -Group together and form on the surface of the skin.
- -If genetic, can be lightened but not removed.
- -Forms in the dermis layer.
- -When damaging radiation destroys active ingredients.
- -Shows on surface of the skin.
- -Skin is thin and sensitive and blemishes get worse.
- -Uncontrollable, abnormal cell division and multiplication.
- -Destruction of normal skin tissue.
- -Poisonous substances that disturbs the cell newel process.
- -Refers to wild cells.
Broken veins and dilated capillaries:
- - Shows red on the surface of the skin. Forms when skin is exposed to extreme temperature changes. This condition can get worse when using exfoliators, toners, alcohol and nicotine.
- -The skin temperature that moves from high to a low temperature, can increase the blood flow.
- -The pressure in this area increases.
- -Skin is thin and sensitive and collagen vessels weakened.
- -There is no support and veins burst.
- -Displays as a thin red vein on the surface of the skin.
- -If red it can be healed, as soon as blue/purple it is permanent.
- -Caused by excessive sebum excretion by the sebum glands. When impurities block the pores and bind with oxygen, the impurities oxidises and forms blackheads.
- -To treat this problem, the sebum secretion must be brought under control.
- -Is caused by blockages under the skin. Impurities and dead skin cells pack together under the epidermis and form a whitehead.
- -Under the eye indicates cholesterol.
- -Next to the eye and on cheeks indicates lung problems.
- -Blockage that oxidises.
- -Caused by insufficient cleansing and the use of the wrong product.
- -Can be prevented by regular masks and sufficient cleansing.
- -Colouring underneath skin, looks almost like a freckle.
Papule/ Blind pimple
- -Blockage of pore that is red and swollen.
Pustule/ Ripe pimple
- -Swollen and irritated – festers.
- -Compact growth under the dermis. Not on outside, but a small ball on the inside.
- -A small superficial water blister after sunburn.
- -A big superficial water blister – e.g. wearing of wrong shoes
- -Caused by pressure or bruising – e.g. if something heavy is carried and a callus is formed
- -Medical condition on the jawbone or breast area (festers), must not be touched
- -Chap in the skin, normally at the soles of the feet. Annorexia, Bellemie and Chemo patients get it in their faces as a result of a shortage of vitamins.
- -Is viral effected tissue that festers and eats the skins away. It damages the nerves in the areas that results in poor function and is contagious
Damaging UV rays
- Damaging UV rays destroy active substances, that is needed to keep the cell healthy and in normal working order.
- Destroyed or hurt cells appear on the surface of the skin as blemishes, pregnancy blemishes and cancer blemishes.
- UV A – causes ageing and destroys elastin.
- UV B – causes sunburn and pigmentation.
- UV C – causes the biggest damage, like cancer.
- -Hormone imbalance caused mostly by the body itself.
- -It can also be caused by pregnancy and contraceptive pills and injections.
- -Hormone imbalance makes the skin hyper sensitive and more acceptable for damaging UV rays.
- -Tissue damage forms easier on the skin.
- -Influence on collagen and elastin.
- -Oestrogen builds the skin – sensitivity and oiliness.
- -Progesterone degrades the skin – ageing and dehydration.
Use of soap
- -Most soap is alkaline. Alkaline substances are chemicals that destroy the epidermis layer. Tissue damage occurs, and the skin is left hyper sensitive. The alkaline that is present in soap disturbs the normal pH of the skin. The normal, protective layer of the skin is high in acid. As soon as the acid mantle gets neutralized, the skin is more open for tissue damage.
Use of Vitamin E
- -Vitamin E that is applied externally on the skin may cause contact dermatitis. It is a hyper allergic reaction on the skin where the epidermis layer peels. Skin gets hyper sensitive and tissue damage forms.
- -Damages cells and can cause destruction of active ingredients like enzymes.
- -Reduces Vitamin C in the body. Vitamin C is needed for the absorption of Vitamin D in the skin.
- -If vitamin D absorption is not possible, the collagen and elastin tissue lose their suppleness.
- -Damaging nutrients cause tissue damage in the form of skin cancer.
- -Ingredients in a diet and in some skincare products can be poisonous substances.
- -Exfoliators, alcohol, wind, air conditioners, heaters and air pollution cause tissue damage, because it damages the epidermis which is the protection layer of the skin.