What are sarcomeres?
Sarcomeres are the contractile units of the muscle tissue formed of alternating actin blocks (thin filaments) and myosin blocks (thick filaments). Several sarcomeres placed in linear sequence form a myofibril. Therefore one muscle fiber (cell) has many myofibrils made of sacomeres. The compartments where myofibrils are inserted are delimited by an excitable membrane known as sarcolemma. The sarcolemma is the plasma membrane of the muscle cell.
