Electrical slow action potentials named slow waves are generated by the specialized pacemaking cells present within the gastrointestinal wall. This phenomenon is the basis for the so-called miogenic control of motor activity and the aforementioned cells are identified as the interstitial cells of Cajal. However, the pacemaking function is ascribed solely to the cells of type I and IV, while the cells of types II, III and also of type IV are believed to conduct the electrical signals from the intramural ganglionic neurons to the smooth muscle cells. The similarity of the interstitial cells of Cajal to other cells, especially to the neurons, fibroblasts or myocytes accomplishes their precise identification.