الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
The skin is the largest organ of humans and animals that protects the body from the harsh external environment by providing a barrier. The skin works by blocking the entrance of harmful materials to organisms, regulating the temperature, water, and electrolyte. The skin is made of the epidermis and dermis layers these layers may be divided again into several sub-layers depending on the site of the skin. The epidermis is an outside part of the skin that is seen and contains melanocytes, Merkel cells, Langerhans cells, keratinocytes. The dermis layer consists of the extracellular matrix that is synthesized by fibroblasts (collagens, glycosaminoglycans, elastin). When a disruption of these layers occurs the skin will undergo the normal physiological activities that will facilitate the closing of the barrier. These activities may be at the cellular, molecular, biomedical levels, these activities are shown through these four mechanisms, Hemostasis, Inflammation, Proliferation, and Remodeling.