The different layers, nerves & glands of the skin are known as the structure of the skin. Skin is a protein called ‘soft keratin’. There are three layers of the skin 1. Epidermis 2. Dermis 3. Subcutaneous tissue

The Epidermis The epidermis is the outer or top layer and is made up of five sub layers. From the top layer they are called Stratum Corneum Stratum Lucidum Stratum Granulosum Stratum Mucosum Stratum Germinativum

Germinativum layer  The Germinativum layer is the bottom layer and here the cells are constantly reproducing. The melanocyte cells are also located in this layer.  As new cells are formed and mitosis takes place, the old cells are pushed towards the surface of the skin.

Mucosum layer The Mucosum layer is where tissue fluid is stored.

Granulosum layer uThe Granulosum layer is where the cells are found with small granules in them, thought to make the skin tough. Your lips and skin under fingernails do not have this layer in them.

Lucidum layer The Lucidum layer is only found on the palms of your hands and soles of your feet. This is the layer that thickens to fight mechanical attack.

Corneum layer The Corneum layer is the top layer of your skin. This is the layer you can see. Here the cells are dead and continually flake off the surface.

The Dermis Layer  This layer is under the epidermis layer and is sometimes called the true skin.  This layer contains the blood vessels.  These divide into a network of smaller vessels called capillaries.  The blood supplies essential materials for growth, nourishment and repair of the skin.

 Nerves found in the dermis layer are sensitive to pressure, pain, heat touch and cold.  The nerves of the skin act as warning systems to the body and alert us to temperature changes, degrees of pressure, whether something is hard or soft. The Dermis Layer

 The body will react to pain, pressure or degrees of temperature.  It is through these nerve endings that the dermis layer is able to protect the body parts underneath. The Dermis Layer

The dermis has two sub layers: Ø Papillary Layer Ø Reticular Layer.

Papillary Layer  This is where blood vessels called capillaries and nerve endings are found.  Melanocytes which produce pigment can be found where the papillary layer joins the epidermis

Reticular Layer  This layer helps give skin its elasticity. In this layer there are Blood and Lymph vessels, nerve & sweat glands.  Collagen is found in this layer and is the most abundant protein in the dermis.

Subcutaneous Tissue nThis is a layer of fatty tissue between the dermis & muscles & bones. n It protects you from injury & helps to keep you warm.

Skin Skin is the largest organ of the body. It is a protective covering for the skeletal system and vital organs. It contains many special structures including : follicles, hair, nails, sweat glands and sebaceous glands. Skin is very elastic and at the surface is a dead substance which is constantly being shed and replaced by new growth.

Skin Our skin is composed of a protein known as keratin. Hair is also composed of this substance

Skin - the differences Skin – Soft Keratin Grows in flat sheets Contains more moisture- than hair Less sulphur - than hair Hair- Hard Keratin Grows in fibers Contains less moisture- than skin More sulphur - than skin

The Functions of skin 1. Sensation 2. Protection 3.Excretion 4.Absorption 5.Regulation 6.Secretion As a hairdresser there are six functions of skin that you need to know about:

Sensation Specialised nerve endings in the skin are able to detect, warmth, coldness, touch and pain.

Protection Your skin protects you in 4 ways: 1.Protection from Physical Attack  Physical attack is when your skin is hurt. Eg., shoes rubbing on your heels, your skin will thicken & make corns or calluses to protect that area of your body.

Protection 2. Protection from Chemical Attack When your skin is damaged by chemicals such as perm solution or soap.  Sebum helps stop skin from drying out.

Protection 3. Protection from Bacteria The acid mantle (sweat & sebum) which has an acid pH helps stop bacteria getting into the skin. Bacteria does not like acidic conditions.

4. Protection from Ultra Violet Rays.  The natural pigment in skin (melanin) helps protect the skin from sunburn.

Excretion  The sweat glands in the skin excrete sweat which is a waste product of the body.  Sweat helps to control body temperature.

Absorption The skin absorbs health - giving vitamins through the action of ultra-violet rays upon the skin.

Regulation The skin helps regulate the body temperature by means of perspiration.

Secretion  Sebum is an oil that is secreted from the sebaceous gland.  It helps to waterproof the skin & stops it from drying out.  When sweat & sebum mix together on the skin they make an acid barrier called the ACID MANTLE.

Acid Mantle When sebum and sweat mix together on the surface of the skin they form an emulsion on the skin that is called the acid mantle. This thin film of liquid protects the skin, by making it waterproof and by preventing harmful bacteria from entering the skin.

Certain bacteria and fungi are able to exist on the outside of the skin and it is their action against the acid mantle that can create extreme body odour. If the acid mantle of the skin is removed, protection of the skin is lost. Acid Mantle