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Skin Biology . Lesson 2 Unpacking the Structures and Functions of the skin . By the end of this session you should by able to: . Did you know?. Our body structures . CELLS. Basis of all life starts from a cell Cells are tiny units of life . All cells have three things in common.
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Skin Biology Lesson 2 Unpacking the Structures and Functions of the skin
CELLS • Basis of all life starts from a cell • Cells are tiny units of life
Tissues Not the kleenex kind!
Four groups of human tissues Tissue means – a group of similar cells that perform a specialised function • Epithelial – cellular tissue covering a free surface, classified into types based on the number of layers and the shape of the cells The epidermis • Connective – serves to support and bind tissues together. A basic type of tissue that includes bone, cartilage and fibrous tissue collagen and elastin • Muscular – a contractile organ in response to stimulus arrector pili muscle • Nervous – responsible for receiving and transmitting messages. Initiates controls and co-ordinates the body’s ability to adapt to its environment receptors; pain heat, cold, touch. pressure
The skin sections Structurally the skin comprises of two key parts. The thinner portion, composed of epithelial tissue; called the EPIDERMIS. The epidermis is attached to the deeper, thicker layer of connective tissue; called the DERMIS. Within the dermis is the lower subcutaneous layer consisting of adipose tissue. Fibres from the dermis stretch into the subcutaneous layer and anchor onto it. The subcutaneous layer attaches to underlying tissues and organs. This bottom ,lower layer can be known as the: Subcutaneous layer Adipose Layer or Hypodermis
Epidermis- our defense against the world • The epidermis is the outermost layer of skin. • Only 0.1 mm thick • It has five layers, but contains no blood vessels. • Your body reproduces a new epidermis layer approximately every 30 days. • When damaged, the epidermis is capable of healing itself, usually without scarring.
The 5 epidermal layers • Stratum Corneum(Clients) 25-30 layers of dead flat skin made up of keratin, continuously shed and replaced • Stratum Lucidum (Leave) 3-5 layers of clear, flat dead cells found mainly on the soles of feet and palms of hands. • Stratum Granulosum(Gratified) 3-5 layers of flattened cells that develop dark staining granules • Stratum Spinosum(Satisfied) 8-10 layers of polyhedral cells that fit closely together • Stratum Basal / Germinativum (Beautiful) Single layer of cuboidal cells . Contains stem cells and melanocyte. Main purpose is the germination of new cells
Dermis The dermis is the strong, inner layer of skin below the epidermis called the true skin. It supports the epidermis with a blood supply The dermis provides your skin with strength and elasticity. When injured or damaged, the dermis does not regenerate fully and may create scarring
The Hypodermis or subcutaneous layer • Located at the base of the dermis and contains fat cells to cushion and insulate the body • Fibres from the dermis stretch into the subcutaneous layer and anchor the skin to it. • The subcutaneous layer attaches to underlying tissues and organs.
That was the structure (what skin has in it) What about the Function of the skin! What does it do?
Functionsof the Skin Secretion Heat Regulation Absorption Protection Sensation Excretion
S H A P E S ensation Nerve endings allow us to feel: heat, cold, touch, pressure and pain. eat regulation Keeps the bodies internal temperature at 37 degrees bsorption Skin absorbs; small amounts of chemicals, drugs and cosmetics. rotection Protects us against the invasion of bacteria and injury xcretion Sweat glands excrete salt, water and other chemicals through pores of the skin. ecretion Oil glands secrete sebum to maintain the skins moisture levels
Functions of the skin Keeps you warm by providing a layer of fat under the skin
Protects you from bumps, bacteria and friction Strong fibers of collagen elastin Sweat glands to cool you down, and combined with oil glands providing a film – acid mantle – it is your first line of defense
Excretes toxins Removes excess salts and wastes like carbon dioxide and urea
Absorption Creams and Drugs and some medications UV light which Produces colour
The Miracle of skin Skin is a miracle garment. It’s soft, pliable, strong, waterproof and self-repairing