The three main layers of the skin are epidermis, dermis, and subcutis (hypodermis).
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 on this page identifies all of the skin layers as well as the structures found within each layer.
