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UND 363 Retic info
UND 363 Reticular fiber and silver techs.
Question | Answer |
---|---|
reticular fibers have what function and are found where | support, and are found in liver, kidney and spleen |
why demonstrate reticular fibers (examples) | cirrhotic liver will show disturbed patterns of the retic fibers, can also display specific patters in tumors and therefore differentiate different tumor types |
what are the retic fibers usually demod with | silver stains (rely on impregnation of silver ions on fibers and then subsequent REDUCTION of silver ions to a visible metallic form |
what is argyrophilic | retic fibers are argyrophilic meaning that they can absorbe silver from soln' but can't reduce them to a visible form w/o a reducing substance |
what are the 7 steps in silver techs. | oxidation, sensitization, silver impregnation, reduction, toning, removal (of unreduced silver), counterstainig |
explain oxidation | oxidation (glycol to aldehydes), enhances subsequent steps, used oxidizers phosphomolybdic acid, potassuim permanganate, and periodic acid |
explain sensitization | helps initial binding to tissues, is done with uranyl nitrate, dilute soln' silver nitrate. |
explain silver impregnation | silver ions provided by ammoniacal silver soln' will impregnate fibers and replace sensitizer in metal organic cmpd. (can be done with ammoniacal or diamine silver complex) |
What is silver diamine complex composed of | (strong base), ammonium hydroxide added to silver nitrate/potassium hydroxide aqueous soln' which will form the silver diamine complex |
explain reduction | (ie developing), reduction uses formalin to reduce silver diamine to a visible form |
explain toning | Toning is when bound metallic silver is treated with gold chloride. (converted to metallic gold) **is more stable and give better contrast/clarity** |
explain silver removal | unreduced silver is removed by treating the sections with sodium thiosulfate (hypo) |
explain counterstaining | may or may not be used (can use nuclear fast red or lt. green) |