Skin is the largest organ of the human body. For the reason that it makes a barrier between the external environment and the internal organs, it is affected by many bodily diseases and complex external influences. Therefore, it is necessary to understand the basic structure of this organ. Functions of the skin could best be grouped as follows:
- It protects the body against mechanical, chemical and thermal injuries
- It protects the body against pathological microorganisms since it contains many glands that constantly secrete antibacterial substances that prevent the body surface from the colonization of the above mentioned pathogens
- Immunologically active cells in the skin tissue represent one of the most important defense mechanisms against infection
- The skin regulates body temperature through sweat that is secreted by sebaceous glands. Evaporating from large skin areas, the sweat reduces the inner body temperature. Since the skin is filled with blood vessels that make a dense network, the circulation that develops from the deepest parts of the body to the surface maintains the temperature at just about constant values
- It also ensures a constant concentration of water in the tissues by eliminating salt which entails water. On the other hand, the skin does not allow water evaporation and drying of the internal tissues
- Because of the numerous nerve endings, the skin is most sensitive organ that provides a feeling of pressure and pain
Starting from the lowest point to the surface, there are the following noticeably distinguishable skin layers: Subcutis - subcutaneous adipose tissue has a protective role as a thermal insulator and energy "reservoir" Dermis - the middle layer provides strength and elasticity to the skin owing to connective and elastic fibers. Infused with the blood and nerve elements it is the basis of numerous hair follicles and sebaceous glands. Epidermis – the thinnest skin layer that we perceive on surface. It’s stratifiedly arranged cells keratinocytes adjoin the dermis together with melanocytes cells that are responsible for producing melanin, the pigment that defines skin color. On the surface, in the corneous skin layer, the keratinocytes gradually differentiating die and "flake".