Skin and its Care

Abstract

Human skin needs care From the moment of our birth our skin begins to age, as does the whole body, in a natural physiological process [16]. Biological skin aging begins from about the age of 25. Physiological skin aging is accelerated by many external factors like sunlight, cold, UV radiation and air pollution. Too frequent cleansing depletes the skin of its intrinsic components like horny cells, skin lipids and water. In addition, today's diet, lack of exercise, too little sleep, stress and improper care also affect premature skin aging. It is with good reason we say the face is the mirror of our soul. We can tell from a person's face whether he is healthy or happy. Therefore everybody will take care of the facial skin by cleaning, resurfacing and moisturizing. The skin is one of our most complex organs [17]. To stay beautiful and healthy it needs modern treatment methods as well as care and relaxation. With a total area of approximately 2m 2 , the skin is the largest organ of the human body, and it has roughly 4 million receptors (antennas). These are nerves that help us perceive cold and heat and feel pain. Unlike most cells of the body, which no longer divide once they have matured, skin cells continue to divide throughout their entire lifetime. The skin renewal process takes about 28 days. Continuously forming new cells, the cells in the above layers are pushed increasingly upwards to the surface (Fig. 3.1), where they slowly dry out and form the uppermost horny layer of the skin. As the external boundary of the body, the skin has several functions. Among its major functions are protection of the body, regulation of body temperature and sensory perception. To ensure these diverse functions can be fulfilled, healthy skin has a natural protective system consisting of secretions from the sebaceous and sweat glands, the skin's own moisturizing factors, as well as amino acids and lactic Fig. 3.1. Schematic representation of the skin with the top horny layer 16 3 Skin and its Care Fig. 3.2. Creaming sun lotion to the skin acid. This so-called protective acid mantle covers the surface of the skin like an invisible extremely thin film and has a pH that varies between 5 and 6. This is why pH plays an important role in skin cleansing. Products with a pH in this range are said to be neutral or skin friendly. The protective acid mantle of the skin is influenced by sebum and sweat pro-duction. If acids predominate the skin will be dry and feel tight. A predominance of bases will result in oily skin. An important task of skin care is therefore to restore the natural balance of acids and bases. Cosmetic emulsions (Fig. 3.2) play an important role in this arena.