Lesson 2 Skin Biology

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					         Lesson 2
Unpacking the Structures and
   Functions of the skin


                               1
                          Explain simply the
                            organizational
                           structure of the
                             human body
  Explain the                                      List the common
functions of the                                    cell structures
      skin                                         found in the skin


   List the
                                                    State the system
 supporting
                                                      which skin is
   dermal
                                                      classified as:
 structures


     List the layers of
                                                Identify three
    the epidermis and
                                               sections of the
      sections of the
                                                     skin
           dermis
           You are likely to shed some 20
             kilos of skin in a lifetime.



   As an adult, you may have more than 7
  square meters of skin -- about the size of
                  a blanket.


  Right now there are over a million dust
 mites, microscopic critters invisible to the
  naked eye, on your mattress and pillow,
chomping on the dead skin cells that fell off
              you last night!
Our body structures


               CELLS




     TISSUES



                       ORGANS
 Basis of all life starts from a cell
 Cells are tiny units of life
                Cell wall – the outer
                  boundary wall
                  (cell membrane)




Cytoplasm – jelly
 like substance                     Nucleus – the
     filling.                       control centre
 (The fluid part of               (DNA is found
the cell containing                  here)
    organelles)
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
8                    receptors; pain heat, cold, touch. pressure
                    Skin is called the
                  integumentary system



                                                                   Very strong
                                               Discoveries are
Largest organ    Organ and a                                     capable of great
                                Very complex     still being
 in the body    system in one                                      strength and
                                                  about it
                                                                     defenses
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.
Withinthe dermis is the lower
subcutaneous layer consisting of adipose tissue.
Fibresfrom 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
Skin
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.
Epidermal Blood supply
Cell turnover
              stratum corneum


               stratum lucidum


             stratum granulosum


              stratum spinosum

                    stratum
             basal / germinativum




Clients Leave Gratified, Satisfied & Beautiful
 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
 Has 2 levels / layers

The upper papillary layer – connects to the
  epidermis, contains nerve endings and
             blood capillaries

The lower reticular layer – contains fibres that
  allow the skin to expand and contract and
             maintains skin tone.
Structures found in the dermis




                                 23
24
25
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.
Skin facts                           6.52 cm
    65 hairs
 95-100 oil /sebaceous glands

          650 sweat glands

                                         78 heat sensors

                                1300 nerve endings for pain

                                  13 cold receptors

 9,5000,000 cells

17meters of blood vessels

    70 meters of nerves

                                           19,500 sensory cells of nerve fibers


                                       160 pressure apparatuses for tactile stimuli
That was the structure (what skin has in it)

   What about the Function
         of the skin!

           What does it do?
Where would we be Without our skin ?
THE MAIN PURPOSE IS PROTECTION

                            Bacterial
                         Quick wound healing
  Mechanical              Skins acid mantle       Chemical
      Calluses
                                                   detergents
 Sweating /rubbing in
overweight individuals                         household cleaners




                         PROTECTION
Secretion


            Heat
            Regulation



                         Absorption



                                      Protection



                                                   Sensation




                                                               Excretion
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
Keeps you
warm by
providing a
layer of fat
under the
skin
Keeps you cool

     capillaries at the
      surface of your
      skin open up to
      increase blood
     flow and release
      heat from your
         body core



                          glands in the skin
                           produce sweat
                           which cools you
                          by the process of
                             evaporation
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
Removes excess salts
and wastes like carbon
dioxide and urea
Absorption
 Creams and Drugs
 and some
 medications

 UV light which
 Produces colour
SENSATIONS
Skin is a miracle
     garment.
It’s soft, pliable,
      strong,
    waterproof
        and
  self-repairing

				
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posted:11/30/2012
language:English
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