The sinoatrial node triggers an impulse
To generate the electrical impulse which triggers the onset of heart contraction
The Sinoatrial Node sends a wave of electric impulses through the heart, which causes both atria to contract.
SA node sends an impulse for the atria to contract. AV node is then activated which contracts the ventricles.
The heart beats regularly because it has it's own pacemaker. The pacemaker is a small region of muscle called the sinoatrial, or SA, node. It is in the upper back wall of the right atrium. The node triggers an impulse that causes both atrium to contract. Very quickly, the impulse reaches the atrioventricular, or AV, node at the bottom of the right atrium. Immediately, the atrioventricular node triggers an impulse that causes both ventricles to contract.
The Heart's own pace makerThe heart beats regularly because it has it's own pacemaker. The pacemaker is a small region of muscle called the sinoatrial, or SA, node. It is in the upper back wall of the right atrium. The node triggers an impulse that causes both atrium to contract. Very quickly, the impulse reaches the atrioventricular, or AV, node at the bottom of the right atrium. Immediately, the atrioventricular node triggers an impulse that causes both ventricles to contract.
It is supposed to be the sinus node and the conducting tissue. It includes the AV node and bundle of HIS. The sinus node generate the impulse in the heart for contraction. The AV node and bundle of HIS transmits the impulse to the ventricles.
The AV node sends out an electrical impulse that causes the heart to contract.
The electrical impulse in the heart begins in the sinoatrial (SA) node and travels across the walls of the right atrium to the atrioventricular (AV) node. WHie the impulse travels the atria have time to contract. Once the impulse hits the AV node the signal is transmitted to the Bundle of His (AV bundle) and then on the the intraventricular fibers (purkinje fibers) in the septum and the outer chamber walls of the heart . This results in a simultaneous ventricular contraction.
Sinoatrial, or SA node.
The sinoatrial node is impulse generating tissue in the (R) atrium of the heart. It is the natural pacemaker of the heart.
The sinoatrial node, abbreviated SA node, is the natural pacemaker. The SA node is a specialized collection of cells in the right atrium that can depolarize autonomously and do so on a regular basis. It is a bundle of neurons which 'fire' an electrical impulse at regular intervals, causing the heart muscle to contract. After the sinoatrial node has fired, the electrical impulse is sent to other nodes within the heart which then fire in a sequence that produces the heart beat.Sinoatrial node, SA Node