All of the following statements regarding the heart are true EXCEPT
The sinoatrial node receives a nerve supply; however, this node initiates the heartbeat autonomously. The autonomic innervation modulates the rate of depolar­ization of the sinoatrial node, thereby modulating the heart rate. The sinoatrial node is composed of special­ized cardiac muscle cells that depolarize spontaneously at a greater rate than that of other cardiac muscle cells. Because cardiac muscle cells contact each other electrically through gap junctions at the intercalated discs, the depolarization of the sinoatrial node drives the other cardiac muscle cells of the atrium to depolar­ize at the same rate as the node.