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Archives: Dictionary

Langer’s line

Noun 1. Topological lines drawn on a map of the human body. They were historically defined by the direction in which the skin of a human cadaver will split when struck with a spike. They correspond to the natural orientation of collagen fibers in the dermis, and are generally perpendicular to the orientation of the underlying muscle fibers. Langer’s lines have relevance to forensic science and the development of surgical techniques. ( 2. Lines which can be extrapolated by connecting linear openings made when a round pin is driven into the skin of a cadaver, resulting from the principal axis of orientation of the subcutaneous connective tissue (collagen) fibres of the dermis; they vary in direction with the region of the body surface. ( 3. Any of the various linear openings that occur when a pin is driven into the skin of a cadaver, whose appearance depends on the axis of orientation of the subcutaneous connective tissue fibers and whose direction varies with the region of the body surface. (The American Heritage® Medical Dictionary) Syn: cleavage...

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Langerhans cells

Noun 1. Dendritic cells (antigen-presenting immune cells) of the skin and mucosa, and contain large granules called Birbeck granules. They are present in all layers of the epidermis, but are most prominent in the stratum spinosum. They also occur in the papillary dermis, particularly around blood vessels, as well as in the mucosa of the mouth, foreskin, and vagina. They can be found in other tissues, such as lymph nodes, particularly in association with the condition Langerhans cell histiocytosis (LCH). ( 2. Any of the dendritic cells of the interstitial spaces of the mammalian epidermis that appear rod- or racket-shaped and are similar to melanocytes but cannot oxidize phenols. (The American Heritage® Medical Dictionary) See centroacinar...

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Langhans giant cell

1. Large cells found in granulomatous conditions. They are formed by the fusion of epithelioid cells (macrophages), and contain nuclei arranged in a horseshoe-shaped pattern in the cell periphery. Although traditionally their presence was associated with tuberculosis, they are not specific for tuberculosis or even for mycobacterial disease. In fact, they are found in nearly every form of granulomatous disease, regardless of etiology. ( 2. Any of the large cells found in the lesions of some granulomatous conditions (as leprosy and tuberculosis) and containing a number of peripheral nuclei arranged in a circle or in the shape of a horseshoe. ( 3. Multinucleate cells formed by fusion of epithelioid macrophages and associated with the central part of early tubercular lesions. Similar to foreign body giant cells, but with the nuclei peripherally located. ( Syn: Pirogov-Langhans...

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/ləˈn(y)o͞ogō/ Noun 1. Very fine, soft, and usually unpigmented, downy hair on the body of a fetus or newborn baby. It is the first hair to be produced by the fetal hair follicles, and it usually appears on the fetus at about 5 months of gestation. It is normally shed before birth, around 7 or 8 months of gestation but is often present at birth and disappears on its own within a few days or weeks. ( 2. Soft down or fine hair, specifically that covering the human foetus or a tumorous area. ( 3. The fine downy hair covering a human fetus; normally shed during the ninth month of gestation. ( 4. The soft woolly hair which covers most parts of the mammal foetus, and in man is shed before or soon after birth. ( Word origin: Latin lana,...

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