specific dynamic action

specific dynamic action

n. Abbr. SDA

An increase in the production of heat caused by the ingestion of food, especially proteins.

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specific

1. pertaining to a species.

2. produced by a single kind of microorganism.

3. restricted in application, effect, etc., to a particular structure, function, etc.

4. a remedy specially indicated for a particular disease.

5. in immunology, pertaining to the special affinity of antibody for the corresponding antigen.

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specific acquired immunity

see acquired immunity.

specific activity enzymes

enzyme activity as V_max, measured as μmoles of substrate utilized or product produced per minute, expressed on a specific unit of comparison such as per mg protein or g of tissue weight or ml or L of solution such as plasma.

specific drug

one that acts at only one type of receptor but may produce several pharmacological effects depending on which organs carry the operant receptor.

specific dynamic action

heat produced by the metabolism of food and unavoidably lost to the animal. In cold environments it will be contributed to the maintenance of body temperature but in a hot environment it must be dispersed by the normal heat-dissipating mechanisms. Called also heat increment.

specific gravity (sp. gr.)

the weight of a substance compared with the weight of an equal amount of some other substance taken as a standard. For liquids the usual standard is water. The specific gravity of water is 1; if a sample of urine shows a specific gravity of 1.025, this means that the urine is 1.025 times heavier than water. Specific gravity is measured by means of a hydrometer.

specific seasonals

clusters of cases occurring at specific seasons.