运动单位(前角细胞、周围神经纤维、神经肌肉突触和由前角细胞支配的肌纤维)疾病,通常有肌无力、肌张力低、肌萎缩等症状。若疾病限于前角细胞或周围神经,肌无力则为失神经支配性即神经原性肌病。若病变限于肌纤维,肌无力则为肌原性肌病。肌 Motor units (anterior horn cells, peripheral nerve fibers, neuromuscular synapses and muscle cells dominated by the anterior horn cells) disease, usually muscle weakness, low muscle tone, muscle atrophy and other symptoms. If the disease is limited to anterior horn cells or peripheral nerves, muscle weakness is denervated neurogenic myopathy. If the lesion is limited to muscle fibers, muscle weakness is myogenic myopathy. muscle