Final answer:
Intermediate filaments provide structural support to cells by maintaining their shape, anchoring organelles, strengthening cell-cell junctions, and connecting cells to extracellular structures.
Step-by-step explanation:
Intermediate filaments play an essential role in maintaining cell structure and integrity. As part of the cell's cytoskeleton, they are composed of intertwined strands of fibrous proteins, notably keratin. These filaments are named 'intermediate' because of their size being between that of microfilaments and microtubules. The primary function of intermediate filaments is to bear tension thereby maintaining the shape of the cell. They also serve as a scaffold inside the cell to anchor organelles, including the nucleus, ensuring they remain in place. Furthermore, in cells that experience external mechanical stress, such as muscle and skin cells, intermediate filaments contribute significantly to their strength and resilience.
On a broader scale, intermediate filaments are critical in animal tissues, where they fortify cell-cell junctions and connect cells to extracellular structures. Specialized intermediate filaments, like desmin in muscle cells, help resist external forces by transmitting contractile forces across cells, thus aiding in muscle contraction. Similarly, keratin-based intermediate filaments give structural support to the skin, hair, and nails.