I would like to make longer one of the nerve models that come with S4L, it seems like in the "Modify" section, I can extrude single lines (that represent Axons). However, when I select any other volume such as the cylindrical one that option does not show up. Ideally, I would like to select the whole model and extrude it, but I am fine if I must do it individually. Any idea on how to do that?