The sinoatrial node has an intrinsic rate of about 100 beats per minute, but it is normally down regulated by the vagus nerve.
60 - 100
1) Sino-atrial node is master node and atrio-ventricular node is on the path from SA node to impulse to ventricles. 2) SA node has intrinsic rhythme rate of about 72 beats/ minute and AV has intrinsic rhythme rate of about 50 beats per minute. 3) SA node has autonomic ( sympathetic and parasympathetic ) nerve supply and AV node do not have any such supply. 4) SA node regulates the heart rate and AV node slows down the conduction across the path, so that atria gets time to contract, to be fallowed by contraction of ventricles. 5) Disease of the SA node generally leads to sick sinus syndrome. Disease of the AV node generally leads to atrioventricular block.
The SA node (also called the "pacemaker") has an intrinsic rate which modified on a moment-to-moment basis by a variety of factors - neural, hormonal, and mechanical. The part of the brain which does sends the neural input is the brainstem via the Vagus nerve.
SA node effects which neurotransmitter?
In a normally functioning heart, the SA (sinoatrial) node is the pacemaker of the heart, but if it is nonfunctional then the AV (atrioventricular) node would take over. If it isn't working either then the Bundle of His can trigger contractions, and if it isn't working the Perkinje fibers can trigger contractions. Each progressive one has a slower intrinsic heart rate.
The SA node normally functions as the pacemaker for the entire heart because its intrinsic rate is the fastest in the system. From the SA node, impulses spread out over the atria, causing them to contract.
60 - 100
1) Sino-atrial node is master node and atrio-ventricular node is on the path from SA node to impulse to ventricles. 2) SA node has intrinsic rhythme rate of about 72 beats/ minute and AV has intrinsic rhythme rate of about 50 beats per minute. 3) SA node has autonomic ( sympathetic and parasympathetic ) nerve supply and AV node do not have any such supply. 4) SA node regulates the heart rate and AV node slows down the conduction across the path, so that atria gets time to contract, to be fallowed by contraction of ventricles. 5) Disease of the SA node generally leads to sick sinus syndrome. Disease of the AV node generally leads to atrioventricular block.
If the atrial conduction system (the SA node and bachmann bundles) and the ventricular conduction system (the AV node and purkinje system) are completely separated, third degree heart block develops. In this case, the SA node will continue to depolarize the atria at its own intrinsic rate and the ventricles will be depolarized by a focus either in the AV node or in the ventricles.
Its one of these, cant remember which one though: AV node, SA node AV bundle, Purkinje fibres. SA node, AV bundle, Purkinje fibres, AV node. SA node, AV node, AV bundle, Purkinje fibres. Purkinje fibres, SA node, AV node, AV bundle.
The SA node (also called the "pacemaker") has an intrinsic rate which modified on a moment-to-moment basis by a variety of factors - neural, hormonal, and mechanical. The part of the brain which does sends the neural input is the brainstem via the Vagus nerve.
the SA node
The rate and pace of the heart are set by the SA node. There are backup systems in place if the SA node fails to do its job.
Sinoatrial Node (SA node)
The SA node is the "pacemaker" of the heart. Cells in the SA node are called "pacemaker" cells and they direct the contraction rate of the entire heart by generating action potentials.
60-100
sa nodes - av bundle- left bundle branches- purkinje fibers . hope this helps