Question 1

A health care provider who suspects that a patient is having a heart attack will look very carefully at this portion of the ECG.&#10;A)Q- T interval&#10;B)P- R interval&#10;C)S- T segment&#10;D)QRS complex

Accepted Answer

The S-T segment on an ECG is closely monitored in the context of a suspected heart attack (myocardial infarction) because changes or elevation in this segment can indicate ischemia or damage to the heart muscle.

Question 2

This portion of the ECG is associated with ventricular contraction.&#10;A)S- T segment&#10;B)QRS complex&#10;C)Q- T interval&#10;D)P- R interval

Accepted Answer

A

Question 3

During exercise, the heart rate .&#10;A)increases to a set &#34;exercise rate&#34;&#10;B)decreases in inverse relation to the exertion involved&#10;C)increases proportional to the exertion involved&#10;D)decreases slightly, but the contractions are stronger

Accepted Answer

During exercise, the heart rate increases in proportion to the level of exertion involved to meet the increased demand for oxygen and nutrients by the muscles.

Question 4

In sequential order, the components of the intrinsic conduction system, beginning at the SA node, are .&#10;A)subendocardial conducting network (Purkinje fibers), bundle branches, AV bundle, AV node&#10;B)AV node, AV bundle, bundle branches, subendocardial conducting network (Purkinje fibers)&#10;C)AV bundle, AV node, subendocardial conducting network (Purkinje fibers), bundle branches&#10;D)bundle branches, AV node, AV bundle, subendocardial conducting network (Purkinje fibers)

Accepted Answer

The correct sequence for the components of the intrinsic conduction system of the heart, starting from the SA node, is: AV node, AV bundle (bundle of His), bundle branches, and finally the subendocardial conducting network (Purkinje fibers). This pathway ensures the orderly and coordinated contraction of the heart chambers.

Question 5

Bradycardia describes a heart rate of .&#10;A)less than 60 beats/min&#10;B)60- 80 beats/min&#10;C)80- 100 beats/min&#10;D)over 100 beats/min

Accepted Answer

Bradycardia is defined as a heart rate that is slower than normal, specifically less than 60 beats per minute.

Question 6

The T wave of the ECG represents .&#10;A)repolarization of the ventricles&#10;B)repolarization of the atria&#10;C)repolarization of the intrinsic conduction system

Accepted Answer

The T wave on an electrocardiogram (ECG) represents the repolarization of the ventricles, which is the process of the ventricles returning to their resting state after having contracted.

Question 7

The QRS complex is associated with .&#10;A)depolarization of the atria&#10;B)repolarization of the ventricles&#10;C)depolarization of the ventricles&#10;D)depolarization of the ventricular septum

Accepted Answer

The QRS complex represents the depolarization of the ventricles, which leads to ventricular contraction.

Question 8

In the normal heart, the has the highest rate of discharge and sets the rate of depolarization for the heart as a whole.&#10;A)bundle branches&#10;B)AV node&#10;C)AV bundle&#10;D)SA node

Accepted Answer

The SA (sinoatrial) node has the highest rate of discharge among the components listed and is responsible for setting the pace of depolarization for the entire heart, acting as the heart's natural pacemaker.

Question 9

If the AV node is damaged so that it can no longer transmit the signal from the SA node (total heart block), will the ventricles continue to contract? Why or why not?&#10;A)Yes: the AV bundle will keep the heart going at the usual rate.&#10;B)Yes: however, ventricular contractions will no longer follow atrial contractions, and the rate of ventricular contractions will be significantly slowed.&#10;C)No: there are no cells left to pace and coordinate the heart beat.&#10;D)No: the SA node must be intact to pace the system.

Accepted Answer

In the case of total heart block, where the AV node is damaged and cannot transmit signals from the SA node, the ventricles can still contract. This is because the Purkinje fibers and the bundle of His, which are part of the intrinsic cardiac conduction system, can initiate impulses independently, albeit at a slower rate than the SA node. Therefore, while the ventricles will continue to contract, the rate will be slower, and the coordination between atrial and ventricular contractions will be lost.

Question 10

It the interval between R waves is on an ECG is 0.80 sec, then the heart rate is .&#10;A)80 beats/min&#10;B)70 beats/min&#10;C)75 beats/min&#10;D)65 beats/min

Accepted Answer

To calculate the heart rate from an ECG, you can use the formula: Heart Rate = 60 / R-R interval (in seconds). Given an R-R interval of 0.80 seconds, the calculation would be 60 / 0.80 = 75 beats per minute.

Question 11

The electrocardiogram (ECG)shows a record of .&#10;A)electrical activity of the heart muscle&#10;B)the electrical events in the intrinsic conduction system&#10;C)each heart beat (or contraction)

Accepted Answer

The answer of The electrocardiogram (ECG)shows a record of .&#10;A)electrical...

Question 12

A normal Q- T interval is .&#10;A)0)32- 0.38 sec when heart rate is 70 beats/min&#10;B)1)0- 2.0 sec when heart rate is 80 beats/min&#10;C)0)16- 0.18 sec when the heart rate is 60 beats/min&#10;D)0)08 sec when the heart rate is 50 beats/min

Accepted Answer

The answer of A normal Q- T interval is .&#10;A)0)32-...

Question 13

How does holding the breath affect heart rate?&#10;A)heart rate decreases&#10;B)heart rate is unaffected by breath holding&#10;C)heart rate increases

Accepted Answer

The answer of How does holding the breath affect heart...

Question 14

Ventricular fibrillation is _ _.&#10;A)slow, strong ventricular contractions&#10;B)rapid, uncoordinated ventricular contractions&#10;C)fluttering of the atria&#10;D)strong, rhythmic atrial contractions

Accepted Answer

The answer of Ventricular fibrillation is _ _.&#10;A)slow, strong ventricular...

Question 15

The middle and largest deflection wave in a normal ECG is the .&#10;A)T wave&#10;B)P wave&#10;C)QRS complex

Accepted Answer

The answer of The middle and largest deflection wave in...

Question 16

The function of the intrinsic conduction system is to .&#10;A)contract slightly before the cardiac tissue to which it is connected&#10;B)carry branches of the autonomic nervous system to heart muscle&#10;C)ensure that the heart beats in a sequential and coordinated manner&#10;D)maintain the structural integrity of the atria and ventricles

Accepted Answer

The answer of The function of the intrinsic conduction system...

Deck 31: Conduction System of the Heart and Electrocardiography