The cytoskeleton consists of a network of proteins contained within a cell's cytoplasm, the fluid substance between the cell wall and the cell's nucleus. The cytoskeleton is responsible for three major cell functions.
One of the proteins that make up the cytoskeleton is called an intermediate filament. This band of material helps provide mechanical support to the cell. In turn, the support structure also helps determine the distinctive shape of some cells.
The cytoskeleton provides a sort of track within the cytoplasm for the movement of organelles, which are cell subunits that have specific functions within the cell. Movement of material and organelles within the cell walls is important for healthy cell function.
Microtubules, another cytoskeleton protein, help line up chromosomes in preparation for cell mitosis, the dividing of cells. During mitosis, a single cell splits into two identical daughter cells, each with its own nucleus and complement of chromosomes.