Human Anatomy (205)

Functions of Integument

The epidermis has five microscopic layers * See the lab Skin Model 2

Cells of the epidermis illustration
Avascular
Stratum corneum is surface layers of flattened scale-like cells
- Huge quantity of corneum cell lost daily
Stratum basale is single, deepest, layer of cells in contact with dermis.
- Basal cells undergo mitosis and push up toward the surface.
- Cell cycle about 24 hr. (new cells daily)
- keratinocytes produce the protein keratin
  - About 95% of basal cells
  - waterproofs and protects skin
- melanocytes produce the pigment melanin that protects the skin from UV radiation
Three transitionall layers between corneum and basale

Derivatives of the Epidermis

Two layers of Dermis [Dense irregular CT]

Structures located in the dermis

Hypodermis [primarily adipose tissue]

A loose connective tissue that binds skin to underlying muscles.
Contains elastic fibers and fat cells
Thickness of adipose varies in body region
- Gender and age variations
- Forms much of breast in females.
Anatomy and Histology of normal Skin

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