Final answer:
Myocardial conducting cells are specialized cardiac muscle cells responsible for the transmission of electrical signals in the heart, including the Purkinje fibers which rapidly spread impulses in the ventricles.
Step-by-step explanation:
The cells (fibers) of the cardiac conduction system are specialized myocardial conducting cells that are essential for transmitting electrical impulses throughout the heart. These specialized cells include components like the sinoatrial node, atrioventricular node, bundle branches, and particularly the Purkinje fibers. These myocardial conductive fibers extend from the bundle branches and rapidly spread the impulse to the myocardial contractile cells of the ventricles, which are different in that they exhibit properties of a syncytium with branched fibers connected by intercalated discs. The combined action ensures the heart beats in a coordinated and effective manner, pumping blood throughout the body.