| Term 
 | Definition 
 
        | Plasma membrane of muscle cells |  | 
        |  | 
        
        | Term 
 | Definition 
 
        | Cytoplasm of muscle cells, filled with myofibrils |  | 
        |  | 
        
        | Term 
 | Definition 
 
        | Endoplasmic reticulum of muscle cells |  | 
        |  | 
        
        | Term 
 | Definition 
 
        | Protein of thick myofilaments |  | 
        |  | 
        
        | Term 
 | Definition 
 
        | Makes up the thin myofilaments with troponin and tropomyosin |  | 
        |  | 
        
        | Term 
 | Definition 
 
        | A bundle of thick and thin myofilaments |  | 
        |  | 
        
        | Term 
 | Definition 
 
        | The section of myofibril between two Z-lines |  | 
        |  | 
        
        | Term 
 | Definition 
 
        | A multi-nucleate cell containing many myofibrils |  | 
        |  | 
        
        | Term 
 | Definition 
 
        | Unit of muscle consisting of many muscle fibers |  | 
        |  | 
        
        | Term 
 | Definition 
 
        | The meeting point of a motor end plate on the sarcolemma and the axon terminal of a motor nerve cell |  | 
        |  | 
        
        | Term 
 | Definition 
 
        | Dividing line between sarcomeres, attaches to the I-band |  | 
        |  | 
        
        | Term 
 | Definition 
 
        | Section of a sarcomere containing only thin myofilaments |  | 
        |  | 
        
        | Term 
 | Definition 
 
        | Section of a sarcomere containing thick and thin myofilaments |  | 
        |  | 
        
        | Term 
 | Definition 
 
        | Section of a sarcomere containing only thick myofilaments when the muscle is relaxed |  | 
        |  |