What are some distinguishing characteristics?
The cytoskeleton is composed of at least three different types of fibers: microtubules, microfilaments and intermediate filaments.
These types are distinguished by their size with microtubules being the thickest and microfilaments being the thinnest.
- Microtubules are hollow rods functioning primarily to help support and shape the cell and as "routes" along which organelles can move. Microtubules are typically found in all eukaryotic cells.
- Microfilaments or actin filaments are solid rods and are active in muscle contraction. Microfilaments are particularly prevalent in muscle cells but similar to microtubules, they are also typically found in all eukaryotic cells.
- Intermediate filaments can be abundant in many cells and provide support for microfilaments and microtubules by holding them in place.In addition to providing support for the cell, the cytoskeleton is also involved in cellular motility and in moving vesicles within a cell, as well as assisting in the formation of food vacuoles in the cell.