As a domain expert in cardiology, I can explain the concept of automaticity of the heart. "Automaticity" refers to the inherent property of certain cardiac cells to generate and conduct electrical impulses without external stimulation. This is a crucial function for the heart as it ensures the regular and rhythmic contraction of the heart muscle, which is essential for maintaining a steady and appropriate heart rate. The cells responsible for initiating these electrical impulses are known as "pacemaker cells," and they are primarily located in the sinoatrial (SA) node, which is often referred to as the heart's natural pacemaker. The process of automaticity involves a self-perpetuating cycle where the cells undergo a spontaneous change in their electrical charge, moving from a resting state to a depolarized state, and then repolarizing to return to the resting state. This cycle is regulated by ion channels in the cell membrane that control the flow of ions like potassium, sodium, and calcium, which are critical for the generation of the electrical impulses. read more >>

Automaticity is the cardiac cell's ability to spontaneously generate an electrical impulse (depolarize). Cells that are dedicated to the purpose of generating an impulse to maintain a heart rate commensurate with the body's need are called pacemaker cells.read more >>