What events in the heart are occurring during the PR interval and during the QT interval quizlet?

What activity is occurring in the heart during the Q-T interval on the electrocardiogram?

The QT interval represents the time for both ventricular depolarization and repolarization to occur, and therefore roughly estimates the duration of an average ventricular action potential. This interval can range from 0.20 to 0.40 seconds depending upon heart rate.

What is happening in the heart during the Q-T interval quizlet?

The Q-T interval is the section on the electrocardiogram (ECG) – that represents the time it takes for the electrical system to fire an impulse through the ventricles and then recharge. It is translated to the time it takes for the heart muscle to contract and then recover.

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What event is taking place during the Q-T interval quizlet?

Describe the electrical events that occur during the Q-T interval. The Q to T interval includes the beginning of ventricular depolarization through the end of ventricular repolarization.

Which of the following events in the cardiac cycle is marked by the T wave in an ECG quizlet?

Ventricular Diastole

Ventricular relaxation, or diastole, follows repolarization of the ventricles and is represented by the T wave of the ECG. It too is divided into two distinct phases and lasts approximately 430 ms.

What happens during PR interval?

The PR Interval is the time, in seconds, from the beginning of the P wave to the beginning of the QRS complex. The electrical signal passes from the atria to the ventricles through the atrioventricular (AV) node (2). The signal slows down as it passes through this node, allowing the ventricles to fill with blood.

What is the PR segment on an ECG?

The PR segment is the portion of the ECG from the end of the P wave to the beginning of the QRS complex. The PR segment is different from the PR interval, which is measured in units of time. Remember that segments are different than intervals.

During which phase of the cardiac cycle do the AV valves close?

The atrioventricular valves are closed during systole, therefore no blood is entering the ventricles; however, blood continues to enter the atria though the vena cavae and pulmonary veins.

What is occuring in the heart electrically when the QRS complex is being recorded?

The QRS complex is a result of ventricular depolarization and indicates the start of ventricular contraction. The T wave results from ventricular repolarization and signals the beginning of ventricular relaxation. The electrical signal for atrial repolarization is masked by the larger QRS complex.

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What is the period of contraction in the heart?

The period of contraction is called systole. Diastole is the longer of the two phases so that the heart can rest between contractions.

What happens during ST segment?

The ST segment is an interval between ventricular depolarization and ventricular repolarization. It is identified as the end of the QRS complex to the beginning of the T wave. The end of the T wave to the beginning of the P wave is described as the TP segment, which is the zero potential or isoelectric point.

What mechanical event takes place during the S2 sound DUPP of the heart?

The second heart sound, called S2, makes a “dub” sound caused by the closure of the semilunar (aortic and pulmonary) valves following ventricular systole. S2 is split because aortic valve closure occurs before pulmonary valve closure.

What is the function of the four heart valves quizlet?

These valves allow blood to be pumped forward into the arteries, but prevent backflow of blood from the arteries into the ventricles. colloquially known as the heart strings, are cord-like tendons that connect the papillary muscles to the tricuspid valve and the mitral valve in the heart.

What activity in the heart is associated with the first heart sound lub and what activity is associated with the second heart sound dub?

The heart tone “lub,” or S1, is caused by the closure of the mitral and tricuspid atrioventricular (AV) valves at the beginning of ventricular systole. The heart tone “dub,” or S2 ( a combination of A2 and P2), is caused by the closure of the aortic valve and pulmonary valve at the end of ventricular systole.

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Which of the following events in the cardiac cycle is marked by the T wave in an EKG?

The T Wave indicates ventricular repolarization, in which the ventricles relax following depolarization and contraction.

What activity in the heart is associated with the first heart sound lub and what is associated with the second dub?

Normal heart sounds come in pairs. The sounds are often described as a constant “lub-dub, lub-dub.” The first “lub-dub” is the sound of the mitral and tricuspid valves closing. The second “lub-dub” is the sound of the aortic and pulmonary valves closing soon after.