So we have the thick filament shown in purple with the myosin heads that basically attach to our thin filament that is shown in black. Now many of these sarcomeres are connected end to end to form a very long fiber we call the myofibro. So this is our myofibril that consists of many adjacent sarcommirs that are connected end to end. So this is one z line, this is a second z line and this is our sarcomere. And many of these sarcomeres are connected to form the myofibro. Now many of these myofibers are placed inside the cytoplasm of the muscle cell.