Skin anatomy

The skin and common disorders. The skin is the body's largest organ. It covers the entire body and weighs approximately six pounds. The skin includes two primary layers: the epidermis and the dermis. The epidermis has important protective functions. It protects against injury and excessive water loss. It also prevents disease-causing microorganisms from entering the body. The thick dermis contains blood vessels, nerve endings, and glands that respond to heat, pressure, and pain. Beneath the dermis, the subcutaneous layer is made up of loose connective tissue and fat (adipose) tissue. This layer acts as a cushion for the skin, helps maintain body heat, and is a store of energy.