The heart beats due to the presence of pacemaker cells in the sinoatrial node, which emit electrical signals that are then transmitted throughout the heart through the conduction bundle, agitating the cardiomyocytes, which then contract, giving rise to the heart’s beating behavior.
The heart beats due to the presence of pacemaker cells in the sinus node of the heart, which generate a pacing current. The pacing current then travels along the atrioventricular (AV) bundle to the AV node, where the electrical signal excites the atrial muscle, causing it to contract, a process that causes the atrial muscle to beat.
When the electrical signal is conducted to the AV node, it produces a physiologic delay in the AV node, then travels along the Hitchcock’s bundle and Purkinje fibers to the ventricular muscle, ultimately exciting the ventricular myocytes and causing ventricular contraction, which in turn causes the ventricular muscle to beat.
The heart beats, and the contraction of the atrial and ventricular muscles is caused by a small time difference. The contraction of the atrial muscle pushes blood from the atria into the ventricles, while the contraction of the ventricular muscle pushes blood from the ventricles into the aorta or the pulmonary arteries.