Neuromuscular

MUSCLE FIBER ATROPHY


Disuse Atrophy, Severe


Muscle fiber atrophy

All muscle fibers are small

H&E stain

Small Muscle Fibers
  Shapes: Varied
  Surface: Irregular
  Nuclei: Large; Pale

H&E stain


H&E stain
Small Muscle Fibers
  Shapes: Varied
  Surface: Irregular
  Nuclei: Large; Pale
  Sizes: Varied

H&E stain


Congo red stain
Small Muscle Fibers
  Shapes: Varied
  Surface: Irregular
  Nuclei: Large; Pale
  Sizes: Varied

Congo red stain


VvG stain
Small Muscle Fibers
  Shapes: Varied
  Surface: Irregular
  Nuclei: Large; Pale
  Sizes: Varied
  Internal architecture: Variable; Coarse

VvG stain

Disuse atrophy
  Smallest muscle fibers: Type 2 (Dark)

ATPase pH 9.4 stain

Disuse atrophy
  Internal architecture: Moderately coarse
  Smallest muscle fibers: Intermediate stained

NADH stain

Disuse atrophy
  Clustered lipofuscin granules

Acid phosphatase stain

See
  Fiber type disorders
  Fiber type properties

Atrophy: Diffuse, Early


H&E stain
Fiber Sizes
  Mildly small
  Bimodal distribution
Fiber Shapes
  Polygonal
  Surface membrane: Irregular

Gomori trichrome stain


VvG stain
Fiber Shapes
  Polygonal
  Surface membrane: Irregular
Internal Architecture
  Irregular

NADH stain


ATPase pH 9.4 stain
Fiber Types
  Type 2 atrophy faster than Type 1

ATPase pH 4.3 stain

ATPase pH 4.6 stain

Neuromuscular Junctions
  Remain dark stained

Esterase stain

Return to Neuromuscular Home Page
Return to Myopathies with wasting

References
1. Am J Physiol Cell Physiol 2012; Online August

9/26/2017