The cytoskeleton, as the name suggests, provides the physical support for the interior of the cell. You might think of it as “cellular skeleton.” There are three main types of support molecules: actin, tubulin, and intermediate filaments. All the muscles fibers in your body are mainly composed of these support molecules. These molecules also build an internal highway within the cell, upon which almost everything is transported. This unit will explore all three molecules in detail and provide some important examples of what they combine to create.