What are the functions of the cytoskeleton?

As the name indicates, the cytoskeleton is responsible for the support of the normal shape of the cell; it also acts as a facilitator for substance transport across the cell and for the movement of cellular organelles.

 For example, the sliding between actin-containing filaments and the protein myosin creates pseudopods. In cells of the phagocytic defense system, like macrophages, cytoskeleton is responsible for the plasma membrane projections that engulf the external material to be interiorized and attacked by the cell.