An intercalated disc is an undulating double membrane separating adjacent cells in cardiac muscle fibers. Intercalated discs support synchronized contraction of cardiac tissue. They can easily be visualized by a longitudional section of the tissue. Three types of membrane junctions exist within an intercalated disc - fascia adherens, macula adheren, and gap junctions. Fascia adherens are anchoring sites for the closest sarcomere. Macula adherens stop seperation during contraction by binding the cells together also called a desmosome. Gap junctions allow action potentials to spread between cardiac cells by permitting the passage of ions between cells, producing depolarization of the heart muscle. When observing cardiac tissue through a microscope, intercalated discs are an identifying feature of cardiac muscle. Cardiac muscle is a type of striated muscle found within the heart. ...