MSCT Week 3: Skeletal Muscle Pathology Flashcards
Satellite Cells
Myofiber associated stem cells called satellite cells that can contribute to regeneration following injury
ONE SLOW RED OX
- Type 1
- Dark meat red legs these are high in oxidative activity, low in glycolytic capacity and red grossly because of high myoglobin and mitochondrial content
- they contract slowly but are capable of continuous and repeated contraction
Two Fast White Sugar
- Type II
- White meat
- low in oxidative activity
- high in glycolytic capacity
- fast contracting
- cannot maintain repeated contraction
Neurogenic Atrophy
Clinical Clues
Nerve Damage (often associated with sensory features)
Neurogenic Atrophy
Histopathologic Features
2 Listed
- Fiber Type Grouping
- Group Atrophy
Neurogenic Atrophy
Etiology
Motor Nerve Damage
Disuse/Steroid Atrophy
Clinical Clues
3 Listed
- Bedridden/ICU
- Corticosteroids
- Hyperthyroidism
Disuse/Steroid Atrophy
Histopathologic Features
Type II myofiber atrophy
Disuse/Steroid Atrophy
Etiology
Atrophy of Fast Twitch Fibers
Dystrophin Related Myopathy
Clinical Clues
Childhood onset
Dystrophin Related Myopathy
Histopathologic Features
5 Listed
- Myofiber size variability
- Necrosis
- Regeneration
- Endomysial fibrosis
- Fatty Replacement
Dystrophin Related Myopathy
Etiology
- Hereditary abnormalities of dystrophin or related proteins
- DMD gene
Inflammatory Myopathy
Clinical Clues
2 listed
- Adult-onset
- associated rheumatologic features
Inflammatory Myopathy
Histopathologic Features
3 listed
- Inflammation (usually T-cells)
- Necrosis
- Regeneration
Inflammatory Myopathy
Etiology
Autoimmune
Congenital Myopathy
Clinical Clues
2 Listed
- Onset at birth
- Floppy Infant