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Overview of Skin Layers

The three main layers of the skin are outlined below:

Epidermis
  • Outer layer and protective surface of the skin
  • Stratified (multiple cell layers) squamous (flattened cells) epithelium that generates keratin and melanin
  • Has five layers made up of differentiating cells (keratinocytes): basal, spiny, granular, lucid, and keratin
  • Basal layer rests on the basement membrane, which is next to the dermis
  • Keratin layer is the outermost layer, with various cell layers in between
  • Melanocytes are present at the base of the epidermal layer
  • Melanoma, basal cell, and squamous cell carcinomas originate in the epidermis
Dermis
  • Elastic layer just beneath the epithelial basement membrane (elastic makes skin shave biopsies curl)
  • Dermal papillae are finger-like projections that extend into the epidermis and together act like a fastener to keep the skin flexible and durable
  • Contains collagen and elastic tissue, blood vessels, nerves and sensory receptors, hair follicles, oil and sweat glands
  • Skin cancer may proliferate into this layer
Subcutis (hypodermis)
  • Just beneath the dermal layer
  • Comprised of adipose (fat) tissue, collagen, blood vessels, and nerves
  • Shock absorber and thermal insulator
  • This layer may be affected by skin cancer as well
The image identifies all of the layers, as well as the structures found within each layer of skin.