How is the pacemaker signal created?

The correct answer is based on the principle of how pacing signals are generated in a pacemaker device. Specifically, a normal conduction system naturally generates electrical impulses that control the heart rate. In a pacemaker, a gradient is created across the cathode and anode, which allows for the appropriate timing and conduction of these impulses.

This gradient is essential for the pacemaker to mimic natural electrical activity in the heart. The cathode (negative electrode) is where the electrical signal originates, while the anode (positive electrode) helps complete the electrical circuit. The design of the pacemaker and the placement of these electrodes facilitate the delivery of electrical impulses that stimulate the heart to contract, thereby regulating the heart rate in patients with certain types of arrhythmias.

The other choices do not accurately describe the pacemaker signal generation process. A battery discharge mechanism is involved in powering the device but does not directly create the pacing signal. External electrical stimulation suggests a scenario where stimulation is administered from outside the body, which is not how implantable pacemakers function. Lastly, while chemical reactions do occur in batteries, they are not the method by which a pacemaker signal is created; instead, they are integral to powering the device rather than contributing to the production of the