Now, it's the heart that actually generates the electrical signal itself, but the autonomic nervous system is capable of regulating the rate of that heart. So, although the base heart rate is set by the essay note, and that's why we call it the natural pacemaker of the heart, our autonomic nervous system can regulate the heart rate as needed. For example, if we need the heart to actually pump quicker, the sympathetic nervous system can actually cause the heart to basically pump quicker. But if we need to rest the heart, if the pace needs to be lowered, the parasympathetic nervous system, via the vagus nerve that innovates the cardiac muscle cells can basically extend into the heart and cause that rate to lower. In fact, because the essay node generates a rather quick pace, what the parasympathetic system does is actually lowers that base pace that is created by the heart itself. Now, medically, the electrical conduction of the heart can be monitored and this is known as the electrocardiogram.