The skin is the largest organ of the body.
Skin is composed of living and dead layers.
The dead layers include the surface scale, outside hair and exposed nail plate. The living layers include the epidermis , dermis , subcutaneous and all the structures found within, which include blood vessels, sweat glands, etc. The information needed to understand cancer of the skin is somewhat different from the information necessary to understand the many thousands of other skin diseases. For the purposes of the Web site, this section's discussion will be restricted to the anatomy of the skin and focus less on body chemistry and immune system facts regarding the formation of skin cancer. Note the location of the principle layers and how some structures, such as hair pores, penetrate the layers of the skin.