What is the function of polar fibers in mitosis?

spindle fibers extend from the centrosomes at the poles and attatch to two chromosome pairs at the kinetechore fibers and the centromeres of those chromosomes. The chromosome splits at the centromere and the spindle takes the chromosome Pair on each side to the poles. for details look up prophase, metaphase, anaphase and telophase/cytokenisis on google image...