Cytoskeleton

The Cytoskeleton is a Network of Protein Threads running through the Cytoplasm. In Eukaryotic cells, the protein threads are arranged as Microfilaments (small solid strands)  and Microtubules (tiny protein cylinders. The best way I can think of to remember this is microTUBUles are shaped like tubes!

The cytoskeleton has 4 main functions:

1. Microtubules and microfilaments Support the Organelles,  keeping them in place.
2. They Strengthen the cell and Maintain its Shape.
3. They're responsible for the Movement of Materials within the cell. i.e. during cell division, microtubules contract the Spindle Fibres to separate the chromosomes.
4. The proteins in the cytoskeleton cause the cell to Move. For example, the movement of Flagella or Cilia is caused by the cytoskeletal proteins. so in the case of sperm cells, the cytoskeleton propels the whole cell.