Cells/The Cytoplasm/Microfilaments and Microtubules

Microfilaments And Microtubules
Some cells can move and change shape and organelles and chemicals are moved around the cell. Threadlike structures called microfilaments and microtubules that can contract are responsible for this movement.

These structures also form the projections from the plasma membrane known as flagella (singular flagellum) as in the sperm tail, and cilia found lining the respiratory tract and used to remove mucus that has trapped dust particles (see chapter 4).

Microtubules also form the pair of cylindrical structures called centrioles found near the nucleus. These help organise the spindle used in cell division.