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melanin
(Encyclopedia)melanin mĕlˈənĭn [key], water-insoluble polymer of various compounds derived from the amino acid tyrosine. It is one of two pigments found in human skin and hair and adds brown to skin color; the ...pigmentation
(Encyclopedia)pigmentation, name for the coloring matter found in certain plant and animal cells and for the color produced thereby. Pigmentation occurs in nearly all living organisms. Almost all plants synthesize ...sunburn
(Encyclopedia)sunburn, inflammation of the skin caused by actinic rays from the sun or artificial sources. Moderate exposure to ultraviolet radiation is followed by a red blush, but severe exposure may result in bl...tyrosine
(Encyclopedia)CE5 tyrosine tīˈrəsēn [key], organic compound, one of the 20 amino acids commonly found in animal proteins. Only the l-stereoisomer appears in mammalian protein. It is not essential to the huma...skin cancer
(Encyclopedia)skin cancer, malignant tumor of the skin. The most common types of skin cancer are basal cell carcinoma, squamous cell carcinoma, and melanoma. Rarer forms include mycosis fungoides (a type of lymphom...urinalysis
(Encyclopedia)urinalysis yo͝orˌənălˈĭsĭs [key], clinical examination of urine for the purpose of medical diagnosis. Urine is initially examined for such characteristics as color, odor, and specific gravity. ...cuttlefish
(Encyclopedia)cuttlefish, common name applied to cephalopod mollusks that have 10 tentacles, or arms, 8 of which have muscular suction cups on their inner surface and 2 that are longer and can shoot out for graspin...neoplasm
(Encyclopedia)neoplasm or tumor, tissue composed of cells that grow in an abnormal way. Normal tissue is growth-limited, i.e., cell reproduction is equal to cell death. Feedback controls limit cell division after a...skin
(Encyclopedia)CE5 Cross section of skin skin, the flexible tissue (integument) enclosing the body of vertebrate animals. In humans and other mammals, the skin operates a complex organ of numerous structures (so...Browse by Subject
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