Skeletal muscle does not contain any type of cell-to-cell junctions, including gap junctions. Gap junctions are found in cardiac and smooth muscle, where they function to increase the speed of electrical communication, or depolarization, between cells.
Gap junctions are cell-to-cell connections that allow for the passage of molecules or electrical currents through cells. Gap junctions may be large or small in size. They are characterized by the amount of connexins they contain, which are the protein families that make up junctions. In addition to gap junctions, other types of junctions include anchoring junctions and desmosomes, which keep muscle cells connected when they contract.