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A man put a frozen turkey into a pot of boiling water and it exploded on…

- - - - Papillary Layer : superficial layer of loose areolar connective tissue, contains dermal papillae
      - Reticular Layer : 80% of dermal thickness, dense irregular connective tissue,
    - - Four types
        
        Melanocytes: produce melanin, gives pigment to the skin
        
        Dendritic (Langerhans) Cells: patrol epidermis, key activators of immune system
        
        Keratinocytes: produce keratin , protective properties
        
        Tactile (Merkel) Cells: sensory receptors that sense touch
      - Layers of Epidermis
        
        Stratum Spinosum: "prickly layer," several layers thick, layers of kertinocytes
        
        Stratum Granulosum: four to six flattened out cells, keratinization begins, cells above this layer die
        
        Stratum Basale: "basal layer," deepest of all the epidermal layers, and firmly attached to dermis
        
        Stratum Lucidum: "clear layer," found only in thick skin, two to three layers of clear, flat, dead keratinocytes
        
        Stratum Corneum: "horny layer," 20-30 rows of flat, anucleated, keratinized dead cells
        
        Thin Skin: covers most of the body, lacks stratum lucidum,
        
        Thick Skin: palms fo hands, feet, and surfaces of fingers and toes
  - - - Physical Barrier: block most water and water soluble substances
      - Biological Barriers: epidermis contains phagocytic cells
      - Chemical Barrier: skin secretes sweat, sebum, and antimicrobial, melanin provides protection from UV radiation
    - - Excretion: skin can secrete limited amounts of nitrogenous wastes such as ammonia
      - Metabolic Functions: skin synthesize vitamin D, akin makes collagenase which prevents wrinkles