The metabolism of the epidermis is that the basal keratinocytes gradually move upward with the cell differentiation, and eventually die to form a non-nucleated stratum corneum, and then fall off. It is generally believed that with the increase of age, the basal layer and the spinous layer are disordered, the junction of the epidermis and dermis becomes flat, and the thickness of the epidermis decreases. As the outermost barrier of the human body, the epidermis is in direct contact with the external environment and is most easily affected by various external factors. Epidermal aging most easily reflects the influence of age and external factors on human aging.
In the epidermis of aging skin, the variability of the size, morphology and staining properties of basal layer cells increases, the junction of epidermis and dermis gradually becomes flat, the epidermal nail becomes shallower, and the thickness of the epidermis decreases. Epidermal thickness decreases by approximately 6.4% per decade, and decreases even faster in women. Epidermal thickness decreases with age. This change is most pronounced in exposed areas, including the extensor surfaces of the face, neck, hands, and forearms. Keratinocytes change shape as the skin ages, becoming shorter and fatter, while keratinocytes become larger due to short epidermal turnover, the renewal time of the aging epidermis increases, the proliferative activity of epidermal cells declines, and the epidermis becomes thinner. thin, causing the skin to lose elasticity and wrinkle.
Due to these morphological changes, the epidermis-dermis junction is not tight and vulnerable to external force damage. The number of melanocytes gradually decreases after the age of 30, the proliferative capacity declines, and the enzymatic activity of melanocytes decreases at a rate of 8%-20% per decade. Although the skin is not easy to tan, melanocytes are prone to local proliferation to form pigmentation spots, especially in sun-exposed areas. Langerhans cells are also reduced, making the skin immune function decline and susceptible to infectious diseases.
Skin anlayzer machine can be used to detect facial skin wrinkles, texture, collagen loss, and facial contour to help to detect the facial skin aging.
Post time: May-12-2022
