This video covers the pathogenesis of muscle inflammation known as Polymyositis, its reactions, targets, symptoms, diagnosis, immune-mediated response and associated causes and treatment. Polymyositis is a disease that causes muscles to become irritated and inflamed. Basic polymyositis is described in it. do watch for basic knowledge of polymyositis (PM). TIMELINE: 0:02 Introduction 0:20 Immune-mediated PM 1:20 Cytotoxic T cell 2:15 Antibodies reaction PM 2:40 Reactions 3:19 Targets 3:36 Inflammation 4:14 Symptoms 4:50 Diagnosis 5:16 Treatment 5:30 Conclusion 6:05 End