cardiac impulses originate at the sinoatrial node in the heart.
cardiac impulses originate at the sinoatrial node in the heart.
where do cardiac impulses originate in the heart?
sinoatrial node
in a healthy heart all activities and rests during each individual cardiac cycle, or heartbeat, are initiated and orchestrated by signals of the heart's electrical conduction system, which is the "wiring" of the heart that carries electrical impulses throughout the body of cardiomyocytes, the specialized muscle cells of the heart. these impulses ultimately stimulate heart muscle to contract and thereby to eject blood from the ventricles into the arteries and the cardiac circulatory system; and they provide a system of intricately-timed and persistent signaling that controls the rhythmic beating of the heart muscle cells, especially the complex impulse-generation and muscle contractions in the atrial chambers. the rhythmic sequence (or sinus rhythm) of this signaling across the heart is coordinated by two groups of specialized cells, the sinoatrial (sa) node, which is situated in the upper wall of the right atrium, and the atrioventricular (av) node located in the lower wall of the right heart between the atrium and ventricle. the sinoatrial node, often known as the "cardiac pacemaker", is the point of origin for producing a wave of electrical impulses that stimulates atrial contraction by creating an action potential across myocardium cells.
cardiac cycle
section::::clinical significance.:diseases.:cardiac arrhythmias.









































while in the healthy heart, waves of electrical impulses originate in the sinus node before spreading to the rest of the atria, the atrioventricular node, and finally the ventricles (referred to as a normal sinus rhythm), this normal rhythm can be disrupted. abnormal heart rhythms or arrhythmias may be asymptomatic or may cause palpitations, blackouts, or breathlessness. some types of arrhythmia such as atrial fibrillation increase the long term risk of stroke.
heart