degradation of motor neurons, conceptual 3d

motor neuron neuromuscular junction myoneural muscle fiber signal transmission contraction movement nervous system synapse disease genetic congenital syndrome spinal 3d illustration demyelination demyelinating multiple sclerosis muscular neuronal myelin sheath inflammatory neuropathy myelopathy progressive degeneration degenerative neurodegenerative atrophy amyotrophic lateral bulbar palsy pseudobulbar primary monomelic amyotrophy degradation destruction damage weakness lou gehrig