THE CYTOSKELETON

Besides its organelles, the cytoplasm contains a network of microtubules, microfilaments, intermediate filaments, and thick filaments (Fig. 4-7). Because they control cell shape and movement, these structures are a major component of the structural elements called the cytoskeleton.

RE 4-7 Microtubes and microfilaments of the cell. The microfil-aments associate with the inner surface of the cell and aid in cell motility. The microtubules form the cytoskeleton and maintain the position of the organelles.