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After the peak of action potential, called spike potential, the permeability of the membrane to Na+ decreases, while it becomes more permeable for K+ which rapidly diffuses out from the cytoplasm to extracellular fluid due to electrochemical gradient. Soon, this part of membrane regains its original polarity and becomes electropositive on outside and electronegative on inside. This is known as REPOLARIZATION and the nerve fibre is called repolarized nerve fibre. A repolarized nerve fibre has same polarity as that of a polarized nerve fibre but has different ionic distribution. It has more K+ outside and more Na+ inside. The repolarized nerve fibre undergoes a refractory period of a few milliseconds during which the original ionic distribution is restored by a sodium pottasium exchange pump which actively transport sodium ions out and pottasium ion in.

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Atrial repolarization coincides in time with?

the ventricular depolarization, which masks the atrial repolarization wave on the electrocardiogram. This is because the QRS complex is much larger than the atrial repolarization wave and overlaps with it, making it difficult to distinguish on the ECG.


Why is the ECG event indicating atrial repolarization not seen in an ECG?

It is on page 374 of your lab book assuming this is the same question that came out Lab 28 in the Ninth Edition of Seeley's Anatomy & Physiology. The atrial repolarization occurs during ventricualr depolarization and is masked by the larger QRS complex. I actually did my homework :)


Which phase of the ECG indicates ventricular excitation and contraction?

The QRS complex on an ECG indicates ventricular excitation and contraction. It represents depolarization of the ventricles as they prepare to contract and pump blood out to the rest of the body.


Why does the lub sound occur around the peak of the R wave?

The lub sound occurs around the peak of the R wave in an ECG because it is associated with closure of the mitral and tricuspid valves, which happens at the beginning of ventricular contraction. This coincides with the R wave, which represents ventricular depolarization and the onset of ventricular systole.


What is moderate high lateral repolarization disturbance?

Moderate high lateral repolarization disturbance typically refers to changes in the electrical activity of the heart that can be seen on an electrocardiogram (ECG). This can indicate potential issues with the heart's ability to repolarize properly, which may be due to underlying heart conditions. It is important to further evaluate these changes with additional testing and follow-up with a healthcare provider for a proper diagnosis and management.

Related Questions

What portion of the ECG indicates ventricular repolarization?

The portion of the ECG that indicates ventricular repolarization or recovery is the t wave. It is the wave found after the QRS complex (Ventricular depolarizaton) in a normal ECG


What is the portion of the ECG that indicates ventricular repolarization?

The wave indicating atrial repolarization wave is hidden by the QRS complex. Ventricular repolarization is indicated by the T wave.


Atrial repolarization coincides in time with?

the ventricular depolarization, which masks the atrial repolarization wave on the electrocardiogram. This is because the QRS complex is much larger than the atrial repolarization wave and overlaps with it, making it difficult to distinguish on the ECG.


Deflection waves in an ECG tracing include?

the T wave, which indicates ventricular repolarization


The deflection waves in an ecg tracing include?

The deflection waves in an ECG tracing include the P wave (atrial depolarization), QRS complex (ventricular depolarization), and T wave (ventricular repolarization). Each of these waves represents different electrical activity of the heart during a cardiac cycle.


What do P, QRS, and T waves represent in an electrocardiogram (ECG)?

The P wave represents atrial depolarization, the QRS complex represents ventricular depolarization, and the T wave represents ventricular repolarization in an electrocardiogram (ECG).


Why is PQRST used in the ECG waves?

PQRST represents the five key components of a normal cardiac cycle on an ECG trace: P wave (atrial depolarization), QRS complex (ventricular depolarization), T wave (ventricular repolarization), and sometimes the U wave (late ventricular repolarization). Analyzing these waves helps to identify abnormalities in the heart's electrical activity.


What does the t wave represent on an ecg?

It represents the repolorization of the ventricles. The ventricles must reset electrically after contracting. In a normal Sinus Rhythm the p wave comes first. Then the QRS complex which is the largest part of the heartbeat will come less than .2 seconds later. The QRS complex usually lasts less than .12 seconds. The final bump is (usually) the T wave.


The T wave tracing measures atrial repolarization?

The T wave on an electrocardiogram (ECG) actually represents ventricular repolarization, not atrial repolarization. Atrial repolarization occurs during the QRS complex and is typically not visible on the ECG due to the larger electrical activity of the ventricles. The T wave reflects the recovery phase of the ventricles after they have contracted and is crucial for understanding cardiac function.


What is the correct order of ECG waves?

P wave - represents atrial depolarization (contraction) QRS complex - ventricular depolarization T wave - ventricular repolarization (relaxation) atrial repolarization is "buried" within the QRS Complex


Why is the ECG event indicating atrial repolarization not seen in an ECG?

It is on page 374 of your lab book assuming this is the same question that came out Lab 28 in the Ninth Edition of Seeley's Anatomy & Physiology. The atrial repolarization occurs during ventricualr depolarization and is masked by the larger QRS complex. I actually did my homework :)


What are the three characteristic waves a normal ecg has?

A normal ECG consists of three characteristic waves: the P wave, representing atrial depolarization; the QRS complex, representing ventricular depolarization; and the T wave, representing ventricular repolarization. These waves reflect the electrical activity of the heart during a cardiac cycle.