However, both the h zone and the eye band do change. In the case of our eyeband, it decreases, but in the case of our h band, it disappears entirely because the h zone is based, not the h band, the h zone. The h zone contains only our thick filament. And in this particular case, because we have an overlap, there is no region where we only have arithic filament. So in this particular diagram, the h zone disappears altogether. So once again, only cardiac muscles, muscles in the heart and skeletal muscles that are responsible for voluntary motion consist of these individual subunits.