Skeletal Muscle & Peripheral Nerve Flashcards
What are the muscle fibre types?
I - Slow twitch, fatigue resistant
IIa - Fast twitch, fatigue resistant
IIb - Fast twitch, fatigue sensitive
What are the types of myopathies?
Inflammatory
Structural
Metabolic
Congenital
Which herbal medicine is associated with myopathies?
Tryptophan
Which diseases should be excluded in a patient with myopathy?
Malignancy
Thyroid pathology
What is myophagia? What condition is it typical of?
Inflammatory infiltration and phagocytosis of muscle fibres
Polymyositis
What is the ag in polymyositis?
Sarcolemma MHC-I
What is seen on pathology in inclusion body myositis?
Interstital monocellular infiltrate
Rimmed vacuoles in fibres
No active phagocytosis
Amyloid
What are some pathological features of dermatomyositis?
No prominent inflammatory infiltrate
Perifascicular atropy
Expression of MAC on blood vessel walls and sarcolemma
Which protein is aberrant in Duchenne muscular dystrophy?
Dystrophin
What are some histopathological features of Duchenne’s?
Variable size of muscle fibres
Apoptosis of fibres
Splitting of membrane
What is acid maltase deficiency cause? What is another name for it?
Aberrant accumulation of glycogen in muscle fibres causing myopathies
Pompe’s disease
What are some common lipid storage diseases?
Carnitine deficiency
Carnitine palmitoyltransferase deficiency
What are the three groups of metabolic myopathies?
Glycogen storage
Lipid storage
Mitochondrial myopathies
What histopathological feature is typical of mitochondrial myopathies?
Ragged red muscle fibres
Where in the PNS does pathology occur to cause neurogenic muscle disorders?
Upper motor neurons
Loss of neurons from anterior horn of spinal cord
Peripheral nerve
