11. In the sarcoplasm are the myofibrils . 12. Between the myofibrils are the mitochondria. 13. The weakened contractile function of skeletal muscle is also linked to the state of the myofibrils . 14. Within the cells of the muscle are myofibrils , which themselves are bundles of protein filaments. 15. Most of the sarcoplasm is filled with myofibrils , which are long protein cords composed of myofilaments. 16. Each muscle fiber is composed of long tubes called myofibrils which in turn are composed of filaments. 17. Ultrastructural examination revealed a loss of lateral alignment of adjacent myofibrils with their Z-lines misaligned. 18. Myofibrils are complex strands of several kinds of protein filaments organized together into repeating units called sarcomeres.19. This drug is known to have toxic effects on myofibrils , resulting in muscle pain and tenderness. 20. They are generally much smaller than the contractile cells and have few myofibrils which gives them limited contractibility.
