the cardiac pacemaker is the part of the cardiac conduction system that is pacing the heart.
what part of the cardiac conduction system is pacing the heart?
the cardiac pacemaker
sometimes an ectopic pacemaker sets the pace, if the sa node is damaged or if the electrical conduction system of the heart has problems. cardiac arrhythmias can cause heart block, in which the contractions lose any useful rhythm. in humans, and occasionally in animals, a mechanical device called an artificial pacemaker (or simply "pacemaker") may be used after damage to the body's intrinsic conduction system to produce these impulses synthetically.





























section::::control.





























section::::control.:primary (sa node).
cardiac pacemaker
if embryonic heart cells are separated into a petri dish and kept alive, each is capable of generating its own electrical impulse followed by contraction. when two independently beating embryonic cardiac muscle cells are placed together, the cell with the higher inherent rate sets the pace, and the impulse spreads from the faster to the slower cell to trigger a contraction. as more cells are joined together, the fastest cell continues to assume control of the rate. a fully developed adult heart maintains the capability of generating its own electrical impulse, triggered by the fastest cells, as part of the cardiac conduction system. the components of the cardiac conduction system include the atrial and ventricular syncytium, the sinoatrial node, the atrioventricular node, the bundle of his (atrioventricular bundle), the bundle branches, and the purkinje cells.
cardiac physiology