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Langer's Lines
Langer's lines, Langer lines of skin tension, or sometimes called cleavage lines, are topological lines drawn on a map of the human body. They are parallel to the natural orientation of collagen fibers in the dermis, and generally perpendicular to the underlying muscle fibers. Langer's lines have relevance to forensic science and the development of surgical techniques. History The lines were first discovered in 1861 by Austrian anatomist Karl Langer (1819–1887), though he cited the surgeon Baron Dupuytren as being the first to recognise the phenomenon. Langer punctured numerous holes at short distances from each other into the skin of a cadaver with a tool that had a circular-shaped tip, similar to an ice pick. He noticed that the resultant punctures in the skin had ellipsoidal shapes. From this testing he observed patterns and was able to determine "line directions" by the longer axes of the ellipsoidal holes and lines. Application Knowing the direction of Langer's lines withi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blaschko's Lines
Blaschko's lines, also called the lines of Blaschko, are lines of normal cell development in the skin. These lines are only visible in those with a mosaic skin condition or in chimeras where different cell lines contain different genes. These lines may express different amounts of melanin, or become visible due to a differing susceptibility to disease. In such individuals, they can become apparent as whorls, patches, streaks or lines in a linear or segmental distribution over the skin. They follow a ''V'' shape over the back, ''S''-shaped whirls over the chest and sides, and wavy shapes on the head. Not all mosaic skin conditions follow Blascko's lines. The lines are believed to trace the migration of embryonic cells. They do not correspond to nervous, muscular, or lymphatic systems. The lines are not unique to humans and can be observed in other non-human animals with mosaicism. Alfred Blaschko is credited with the first demonstration of these lines in 1901. Signs and sym ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |