We have the H zone, we have the A band, we have the Z lines, and we also have something known as the iband, which stretches over to sarcomeres. Now, before we actually discuss what these regions are, let's discuss the composition of our sarcommerce. So what types of proteins are found inside our sarcomir? So we have two types of filaments. We have a thin filament, which are these black horizontal lines. We have 1234-5678 for this particular sarcomere, and we have the thick filament which is shown in purple.