integ lab

• Layers of the Epidermis

  • Stratum corneum
  • Stratum lucidum
  • Stratum granulosum
  • Stratum spinosum
  • Stratum basale
• Stratum Corneum

  1. 15 – 20 layers of flattened non-nucleated keratinized cells

  2. Continuously shed
• Stratum Lucidum

  ONLY in THICK SKIN; translucent layer of flattened eosinophilic cells
• Stratum Granulosum

  1. 3 – 5 layers of flattened polygonal cells

  2. Cytoplasm filled with basophilic masses called KERATOHYALINE GRANULES
• Stratum Spinosum

  1. THICKEST Epidermal layer

  2. Polyhedral cells synthesizing KERATIN filaments (form bundles called TONOFIBRIL which converge and terminate at Desmosomes)
• Stratum Basale/Stratum Germinativum

  1. Single layer of basophilic columnar or cuboidal cells on the basement membrane

  2. INTENSE MITOTIC ACTIVITY
• Cell types in the Epidermis

  • Keratinocytes
  • Melanocytes
  • Langerhans cell
  • Merkel cell
• Keratinocytes are the parenchyma and produce keratin
• Melanocytes are found in the basal layer & junctional zone of dermis and contain tyrosinase for melanin synthesis
• Langerhans cells are dendritic cells containing rod-shaped granules for immunity and are antigen-presenting cells found in the Stratum Spinosum
• Merkel cells are found in the basal layer and are touch receptors
• Layers of the Dermis

  • Papillary dermis
  • Reticular dermis
• Sweat glands are present in the dermis
• Langerhans cell

  Dendritic cells containing rod shaped granules for immunity; antigen-presenting cells found in the Stratum Spinosum
• Merkel cell

  Found in the basal layer; touch receptor
• Dermis layers

  • PAPILLARY DERMIS
  • RETICULAR DERMIS
• Skin glands

  • SWEAT GLANDS
  • SEBACEOUS GLANDS
• Sweat glands type

  • Serous
  • Mucous
• Mechanism of release of excretory products

  • Merocrine
  • Holocrine
• Morphology of skin glands

  • Simple coiled tubular
  • Simple branched acinar
• Papillary Layer of Dermis:

  Fundamental Type of Tissue: Connective Tissue

  Subtype: Connective Tissue Proper

  Specific Subtype: Loose Connective Tissue
• Reticular Layer of Dermis:

  FTT: Connective Tissue

  Subtype: Connective Tissue Proper

  Specific Subtype: Dense Irregular Connective Tissue
• Pilo-sebaceous unit

  • Arrector Pili muscle
  • Sebaceous glands
  • Sweat glands