Histotechnology- Chapter 3 (Instrumentation)verified to pass

Histotechnology- Chapter 3 (Instrumentation)List the equipment in the lab that employs temperature control and state the proper temperature for each instrument. - correct answers Cryostat- -20C (normal), -10C (brain, liver, spleen, lymph node), -25C (Fatty tissue) Flotation Bath- 5-10C Dryer & Oven- 60C Incubator Oven- 37C Fridge- 4C Freezer- -20C Describe light microscopy and identify indications for its use. - correct answers -used for the examination of tissue sections -combines 2 simple microscopes (compass microscope) -image appears dark on a light background Describe Polarizing microscopy and identify indications for its use. - correct answers -primarily used in the identification of crystals or amyloid stained with Congo red -used to examine tissue for substances exhibiting double refraction, an isotropism, and birefringence -achieved by interposing a polarizing device between the light source and the specimen, and inserting a polarizing filter between the specimen and the eye Describe Phase-Contrast microscopy and identify indications for its use. - correct answers -used to examine unstained specimens and allows transparent objects to be seen -not used in routine histology Describe Darkfield microscopy and identify indications for its use. - correct answers -directly transmitted light is excluded, and only scattered or oblique light is used used for study of unstained microorganisms and for silver grains in radioactive staining procedures Describe Fluorescence microscopy and identify indications for its use. - correct answers -light of one wavelength is absorbed by a substance and readmitted as light of a longer wavelength Describe Electron microscopy and identify indications for its use. - correct answers -obtains extra resoling power results by replacing the light source of a light microscope with an electron gun that is emitting electrons State the most common objectives used in light microscopy and the approximate magnification of each. - correct answers -Scanning: X2.5 to X4 -Intermediate: X10 to X20 -High powered dry: X40 to X45 -Oil Immersion: X90 to X100 Describe the method of deterring total magnification. - correct answers Multiplying the magnification of the ocular to the magnification of the objective Clearance angle - correct answers Angle the back of the blade makes with the block Bevel angle - correct answers Angle of the very tip of knife or blade, between cutting facets; normally 27-32°. Wedge angle - correct answers Angle of the edges of the wedge knife. This is the body of the knife or blade; normally 15 degrees. Resolution - correct answers the shortest distance between two points on a specimen that can still be distinguished by the observer or camera system as separate entities. ocular - correct answers the lens that is closest to the eye when someone looks through the device objective - correct answers the lens nearest to the sample