Week 4 - Integumentary System

Week 4 - Integumentary System

1. Skin

   • Function
     • Barrier = Waterproof
     • Temp. Reg = Optimal Con.
     • Excrete = rid toxins
     • Syn. Vit D = Strong Bones
       • Sense = receptors (touch, heat, pain)
     • Indicates Health
       • Anemia - No eye lid colour
       • Jaundice - Yellow Skin
       • Bruise - Tissue Damage
     • Colour/Pigment
       • Dermal Blood Supply
       • Carotene & Melanin
   • Dermis - Connective tissue
     • Epidermis - Epithelium - St.Sq.E
       • 5 Layer
         • Stratum. Corneum
           • Stra. lucidium
             • Stra. Granulosm
               • Stra. Spinosum
                 • Stra. Basale
                   • Where cell division occurs
                 • Keratin (H2O Proof) added to cell
               • Secretes oils and proteins (protection)
             • (ONLY THICK SKIN) - binds in friction
           • Keratin (hard) - tough outer layer.
       • 4 Cells
         • Keratincytes
           • Tactile Cells
             • Langerhans
               • Melanocytes
                 • Produce melanin - UV Protec.
               • Immune Defense
             • Receptors
           • Produce keratin
       • Epidermal Pegs - wavy
       • Avascular
     • Hyperdermis
       • 1 layer
         • Adipose
       • 1 cell
         • Adipocytes
     • 2 layer
       • Papillary
         • Thin collagen fibres - blood supply for the epi
       • Reticulum
         • Net of thick collagen fibres, were most cells located
     • 3 cells
       • Mast Cells
         • Macrophages
           • Fibroblasts
             • Make fibres - collagon and elastin
           • Clean out cell
         • Local immune response
   • Wound healing
     • 1. Formation of Blood Clots (platelets) - seals for defense.
       • Phagocytes clean up debris
     • 2. Fibro genisis - Migration of fibroblasts, make new dermis
     • 3. Migration of epidermal cells - form new dermis
     • 4. Remodelling - scab removal
       • Scar formation due to tension (hypertrophic - over growth)
         • tension lines = langers lines (connective tissue around dermis)
   • Diseases
     • Acne - Sebem Gland
       • Eczema - allergic react.
         • Psoriasis - Overproduc. of keratin cell
           • Tinea - fungal infectino
             • Warts/HSV Cold Sores - Viral
               • Burns
                 • 1st Degree - Epiderm affect
                 • 2nd Degree - Epi + top dermis affect
                 • 3rd Degree - Epi + derm + hypo
                 • Cancer
                   • Basal Cell Carcinoma - s.basal sends mixed messages
                   • Squamous Cell Carcinoma - s.spinosum
                   • Melanoma - areas of pigment
   • Layers

2. Derivatives

   • Hair
     • Bulb → Root → Shaft
     • Three layers - Medulla (middle), cortex, cuticle
   • Nails
     • Root → Body → Bed
   • Glands
     • Sabaceous Gland
       • Produce sebum (lubes & protects)
     • Sweat Gland
       • aprocrine - pheremone secretion
       • merocrine - sweat secretion