Cylindrical organelles, found within muscle cells, that are the contractile unit of muscles
A bundle of thick and thin filaments that forms an organizational unit within a single muscle cell, which contains several myofibrils
Myofibrils are very small fibers that run through each muscle fiber The myofibrils have alternate light and dark bands, which contain protein filaments responsible for the muscle's contractile ability and give the muscle its typical striped appearance under the microscope
Long rodlike (70-80% of volume) organelle of the muscle cell, composed of sarcomeres held in register laterally and longitudinally; the main component of the muscle fiber that constitutes the contractile apparatus