Final answer:
The role of intercalated discs in cardiac muscle is cell communication. They contain gap junctions and desmosomes that allow for the quick transmission of action potentials and the coordinated contraction of the heart.
Step-by-step explanation:
The role of intercalated discs in cardiac muscle is cell communication. They contain two structures called gap junctions and desmosomes, which allow for the quick transmission of action potentials and the coordinated contraction of the entire heart. Gap junctions form channels between adjacent cardiac muscle fibers, allowing the depolarizing current to flow from one cell to the next. Desmosomes anchor the ends of cardiac muscle fibers together to prevent them from pulling apart during contraction.