| Dictionary, Encyclopedia and Thesaurus - The Free Dictionary 1,732,854,583 visitors served. |
|
Dictionary/ thesaurus | Medical dictionary | Legal dictionary | Financial dictionary | Acronyms | Idioms | Encyclopedia | Wikipedia encyclopedia | ? |
heat1 |
0.02 sec. |
|
heat1 energy that raises the temperature of a body or substance; also, the rise of the temperature itself. Heat is associated with molecular motion, and is generated in various ways, including combustion, friction, chemical action and radiation. The total absence of heat is absolute zero, at which all molecular activity ceases. heat1 balance balance between heat loss and heat production; its maintenance is critical to the patient's survival. heat1 bumps see urticaria. heat1 exhaustion a disorder resulting from overexposure to heat or to the sun. Long exposure to extreme heat or too much activity under a hot sun causes excessive sweating which removes large quantities of salt and fluid from the body. When the amount of salt and fluid in the body falls too far below normal, heat exhaustion may result. The same disease in birds is called heat prostration (below). See also heat stroke (below). heat1 increment see specific dynamic action. latent heat1 the heat that a body may absorb without changing its temperature. heat1 loss body heat can be lost by conduction, convection, evaporation and radiation; evaporation is the critical one during exercise and in hot environments. heat1 prostration caused by exposure to high ambient temperature, especially if the humidity causes hyperthermia in birds. This is exacerbated by their poor heat loss mechanisms. heat1 regulation is one of the functions of the hypothalamus and consists of a balancing of the body's heat loss and heat gain by regulation of respiration, skin temperature, sweating and muscle tone. heat1 shock proteins proteins expressed by heat shock (hsp) genes as a result of exposure to increased temperature or other stress. See also heat shock response (below). heat1 shock response decreased transcription and translation activity caused by the synthesis of heat shock proteins by an organism as a result of exposure to increased temperatures or other stress. specific heat1 the number of calories required to raise the temperature of 1 g of a particular substance one degree centigrade. heat1 stress exposure of the animal to high ambient temperatures. heat1 stroke elevation of body temperature above physiologically active levels due to the production of excessive heat, exposure to excessive ambient temperatures or failure to lose heat. Characterized by restlessness, followed by dullness, weakness and recumbency. There is severe hyperthermia, the animal seeks cool places, is dyspneic and lapses into a coma terminally. heat1 teratogenicity is observed only in experimental application of high temperatures in early pregnancy. Observed defects are of the central nervous system, and of the limbs including arthrogryposis and selective shortening. heat1 therapy see hyperthermia. heat1 tolerance in animals is their ability to function well under high environmental temperatures. This capacity varies widely between species and breeds. Much of the difference is due to variations in the capacity to increase heat loss under conditions of heat stress. heat1 weaning the weaning of commercial chickens away from an artificial heat source at about 4 weeks of age. How to thank TFD for its existence? Tell a friend about us, add a link to this page, add the site to iGoogle, or visit webmaster's page for free fun content. |
|
| ? Mentioned in |
|---|
| Medical Dictionary |
| Free Tools: |
For surfers:
Free toolbar & extensions |
Word of the Day |
Help
For webmasters: Free content | Linking | Lookup box | Double-click lookup | Partner with us |
|---|