So let's suppose this is the negative end and this is our positive end and the actin essentially grows beginning from our positive end. And the negative end is attached to some type of structure within the cell. Now, as our actin grows from the positive end of our microfilament eventually it pushes against some type of structure within the cell, for example, the cell membrane. And this gives the cell the ability to resist tensile forces. So microfilaments give the cell tensile strength. So we see that not only are they responsible for our contraction of cells such as the muscle cells, they also stabilize the shape and structure of our cell and they give our cell ten style strength.