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sunburn |
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sunburn, inflammation of the skin caused by actinic rays from the sun or artificial sources. Moderate exposure to ultraviolet radiation ultraviolet radiation, invisible electromagnetic radiation between visible violet light and X rays; it ranges in wavelength from about 400 to 4 nanometers and in frequency from about 1015 to 1017 hertz.
..... Click the link for more information. is followed by a red blush, but severe exposure may result in blisters, pain, and constitutional symptoms. As ultraviolet rays penetrate the skin, they break down collagen collagen , any of a group of proteins found in skin, ligaments, tendons, bone and cartilage, and other connective tissue. Cells called fibroblasts form the various fibers in connective tissue in the body. ..... Click the link for more information. and elastin, the two main structural components of the skin, a process that results in the wrinkled appearance of sun-damaged skin. In addition, the sun damages the DNA of the exposed skin cells. In response, the cells release enzymes that excise the damaged parts of the DNA and encourage the production of replacement DNA (a process that can go wrong and result in skin cancer 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 lymphoma) and Kaposi's sarcoma. ..... Click the link for more information. ). At the same time, the production of melanin melanin , 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 other pigment is carotene, which contributes yellow coloring. ..... Click the link for more information. increases, darkening the skin. Melanin, the pigment that gives skin its color, acts as a barrier to further damage by absorbing ultraviolet light. A suntan results from this attempt by the skin to protect itself. Light-skinned persons and infants are especially susceptible to ultraviolet rays because they lack sufficient protective skin pigment. Certain diseases and drugs may also increase photosensitivity. Due to the increase in the incidence of skin cancer and the effects of ozone layer ozone layer or ozonosphere, region of the stratosphere containing relatively high concentrations of ozone, located at altitudes of 12–30 mi (19–48 km) above the earth's surface. sunburnAcute skin inflammation caused by overexposure to ultraviolet radiation from sunlight or other sources. More common and severe in light-skinned people, it ranges from mild redness and tenderness to intense pain, edema, and blistering, sometimes with shock, fever, and nausea. The process begins after 15 minutes in the sun, but redness starts 6–12 hours later and peaks within a day. Pigment cells in the skin increase melanin production (“tan”). Cold compresses and analgesics reduce pain. Limiting sun exposure, using sunscreen, and wearing protective clothing can prevent severe sunburn. Long-term sun exposure can eventually cause skin cancer, as well as skin wrinkling and thickening. sunburn 1. inflammation of the skin caused by overexposure to the sun 2. another word for suntan sunburn [′sən‚bərn] (medicine) Skin inflammation due to overexposure to sunlight. Want to thank TFD for its existence? Tell a friend about us, add a link to this page, add the site to iGoogle, or visit the webmaster's page for free fun content. |
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