Muscle contraction is a very important activity that enables an organism perform various bodily movements and flexible actions, in response to nerve stimuli. Muscle fibers are multinucleated long cylindrical cells that have an outer membrane called sarcolemma, and are mainly composed of contractile elements called myofibrils (Dougherty, 2016). Myofibrils are made up of repeating units called sarcomeres. Sarcomeres in turn are composed of (thin) actin and (thick) myosin protein filaments called myofilaments (Dougherty, 2016). The muscle fiber structure and organization is shown in Fig 1.
Contraction Mechanism – Sliding Filament Theory
According to the sliding filament theory, during contraction myosin filaments remain constant in length, ...
