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Depolarization of the SA node occurs during which phase?
SA node: P waveUnder normal conditions, electrical activity is spontaneously generated by the SA node, the physiological pacemaker. This electrical impulse is propagated throughout the right atrium, and throughBachmann's bundle to the left atrium, stimulating the myocardium of both atria to contract. The conduction of the electrical impulse throughout the left and right atria is seen on the ECG as the P wave. As the electrical activity is spreading throughout the atria, it travels via specialized pathways, known as internodal tracts, from the SA node to the AV node.
What pacemaker of the heart initiates depolarization under normal conditions?
The primary pacemaker of the mammalian heart is the sino-atrial node. If the SA node fails, the atrioventricular node (AV node) takes over pacemaking.
When threshold is reached at the SA node what channels open causing further depolarization of the membrane?
Fast Calcium
What does a ventricular pacemaker do to initiate a heartbeat?
The SA node (Sinoatrial node) sets the pace for the heart as a whole because no other region of the conduction system or the myocardium has a faster depolarization rate. For this reason, it is the heart's pacemaker.
The spontaneously developing local potential that occurs at the sa node is called the?
pacemaker potential
What generates the p wave of an electrocardiogram?
A P wave denotes atrial depolarization or when your atriacontracts. It is generated by the Sinoatrial (SA) node which is the primary pacemaker and signifies a Sinus Rhythm.
What is the fast rising phase of the SA node action potential is due to?
The fast rising phase of the SA node action potential is due to the opening of voltage-gated calcium channels. This allows an influx of calcium ions into the cell, leading to depolarization and initiation of an action potential.
Immediately before the P wave?
The electrical milestone event that occurs at the P wave of the cardiac cycle of the EKG is atrial depolarization. The upward stroke is right atrial depolarization, and the downward stroke is left atrial depolarization. Normally, this lasts for no more than 0.11 sec.
What is the main pace maker of the heart?
The primary pacemaker of a normal healthy heart is the sinus node (or SA node). It is located in the right atria of the heart.
What electrical activity of the heart is indicated by the p wave?
The P wave on an electrocardiogram (ECG) represents atrial depolarization, which is the electrical activity that triggers the contraction of the atria. This depolarization occurs as the electrical impulse from the sinoatrial (SA) node spreads through the atrial muscle, leading to the atria contracting and pushing blood into the ventricles. The P wave is typically the first deflection in the ECG cycle and is crucial for the proper timing of heartbeats.
Correct order of intrinsic cardiac conduction?
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.
What is the result of parasympathetic stimulation of the SA node?
Parasympathetic stimulation of the SA node decreases heart rate by releasing acetylcholine, which hyperpolarizes the cells in the node and slows down the rate of depolarization. This stimulation is mediated by the vagus nerve, leading to decreased firing of action potentials and a slower heart rate.
