Final answer:
Pacemaker cells are specialized cells that control the heart rate through a process called autorhythmicity, responding to the autonomic nervous system and hormones. They create electrical impulses that regulate the heart's contractions, and their activity can be recorded as an ECG. When necessary, an artificial pacemaker is used to manage and correct irregular heartbeats.
Step-by-step explanation:
The pacemaker cells are specialized cardiac muscle cells responsible for initiating and regulating the heartbeat. These cells have the unique ability to self-excite and depolarize automatically. This capability is called autorhythmicity, and it establishes the base rhythm for the heart’s beating rate. Situated in the sinoatrial (SA) node near the right atrium, the pacemaker cells generate electrical impulses that propagate through the heart. The impulses then reach the atrioventricular (AV) node, passing through the bundle of His, the bundle branches, and the Purkinje fibers, which culminates in the heart's coordinated contraction.
The pacemaker cells respond to signals from the autonomic nervous system (ANS), as well as various hormones, to increase or decrease your heart rate, thus modulating blood pressure as necessary. The electrical activities initiated by pacemaker cells can be traced as an electrocardiogram (ECG), which records the heart's electrical impulses. Additionally, if problems like arrhythmias occur, an artificial pacemaker might be used to restore and maintain a stable heart rhythm and contraction pattern.