Exercise: Muscle hypertrophy
 H & E stain |
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Bimodal distribution of fiber size Larger fibers are hypertrophied and slightly paler than normal sized fibers |
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 Gomori trichrome stain |
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Bimodal distribution of fiber size Larger fibers are hypertrophied and slightly paler than normal sized fibers Some larger muscle fibers with intermediate degrees of sarcoplasmic staining are present |
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 ATPase pH 9.4 |
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Fiber types Larger, hypertrophied fibers are Type 2 (Dark) Smaller fibers are Type 1 (Light) |
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 ATPase pH 4.3 |
 ATPase pH 4.6 |
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Fiber types Larger, hypertrophied fibers are Type 2 (Light) Smaller fibers are Type 1 (Dark) Type 2C fibers (Intermediate) are absent |
Fiber types Some larger, hypertrophied fibers are Type 2A (Very Dark) Some larger, hypertrophied fibers are Type 2B (Intermediate) The degree of staining of 2B fibers is unusually variable Smaller fibers are Type 1 (Light) |
 ATPase pH 4.3 |
Type 2 muscle fibers (pink) are larger than type 1 fibers (dark)
 Cytochrome oxidase stain |
 SDH stain |
 PAS stain |
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Mitochondrial stains Larger, hypertrophied type 2 fibers are Light Smaller, type 1 fibers are dark 3 populations of fibers: Pale (2B), Intermediate (2A) or Dark (1) staining |
Larger muscle fibers are darker stained | |
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1/20/2018