Deck 2: Electrophysiology

Question 1

Which of the following ions has a direct effect on ventricular muscle contraction?

A)Sodium
B)Potassium
C)Magnesium
D)Calcium

Answer 1

D

Question 2

The cardiac cell at rest has what kind of electrical charge?

A)Positive charge
B)Negative charge
C)Neutral charge
D)No charge at all

Answer 2

B

Question 3

The normal ST segment is

A)at the isoelectric line.
B)elevated above the isoelectric line.
C)depressed below the isoelectric line.
D)both above and below the isoelectric line.

Answer 3

A

Question 4

The T wave represents

A)atrial depolarization.
B)atrial repolarization.
C)ventricular depolarization.
D)ventricular repolarization.

Question 5

The term repolarization refers to the

A)heart's mechanical activity.
B)brain's electrical activity.
C)heart's electrical activity.
D)heart's electrical and mechanical activity.

Question 6

The ST segment is located between the

A)P wave and the QRS complex.
B)QRS complex and the T wave.
C)T wave and the next P wave.
D)P wave and the T wave.

Question 7

+20 mV is the

A)resting transmembrane potential.
B)transmembrane potential at the conclusion of phase 3 of the action potential.
C)transmembrane potential at the conclusion of phase 0 of the action potential.
D)transmembrane potential at the beginning of cardiac rest.

Question 8

The relative refractory period extends from the

A)beginning of the T wave to the beginning of the next QRS complex.
B)beginning of the P wave to the beginning of the QRS complex.
C)beginning of the QRS complex to the upstroke of the T wave.
D)upstroke of the T wave to the end of the T wave.

Question 9

The PR segment is located between the

A)P wave and the QRS complex.
B)QRS complex and the T wave.
C)T wave and the next P wave.
D)P wave and the T wave.

Question 10

In the action potential,phase 3 is

A)depolarization.
B)rapid repolarization.
C)plateau.
D)rest.

Question 11

The baseline on the EKG strip is considered to be the

A)PT segment.
B)PR segment.
C)TP segment.
D)QT segment.

Question 12

Phase 0 of the action potential corresponds with what wave or complex on the EKG?

A)T wave
B)QRS complex
C)U wave
D)ST segment

Question 13

The wave or complex that represents ventricular repolarization is the

A)P wave.
B)QRS complex.
C)T wave.
D)U wave.

Question 14

The QRS complex represents

A)atrial depolarization.
B)atrial repolarization.
C)ventricular depolarization.
D)ventricular repolarization.

Question 15

Depolarization is a(n)

A)electrical event that should result in muscle relaxation.
B)mechanical event that should result in depolarization.
C)electrical event that should result in muscle contraction.
D)mechanical event that should result in repolarization.

Question 16

The P wave represents

A)atrial depolarization.
B)atrial repolarization.
C)ventricular depolarization.
D)ventricular repolarization.

Question 17

What electrical event must occur for atrial contraction to occur?

A)Atrial depolarization
B)Ventricular depolarization
C)Atrial repolarization
D)Ventricular repolarization

Question 18

Which of the following is NOT true?

A)Cardiac cells can contract without having been depolarized.
B)Cardiac cells must be depolarized before they can contract.
C)Cardiac contraction occurs as a result of phase 0 of the action potential.
D)Cardiac contraction requires the presence of calcium ions.

Question 19

In the action potential,phase 0 is

A)depolarization.
B)plateau.
C)rapid repolarization.
D)rest.

Question 20

Which of the following correctly describes the relative refractory period?

A)It is the period in which even a weak impulse can cause another depolarization.
B)It is the period in which only a strong impulse can cause another depolarization.
C)It is the period in which no impulses at all can cause another depolarization.
D)It is the period in which the heart function stops temporarily to allow impulse transmission to occur.

Question 21

Which of the following characteristics of heart cells is mechanical?

A)Automaticity
B)Contractility
C)Excitability
D)Conductivity

Question 22

The pacemaker is the ________ of the conduction system of the heart.

A)beginning
B)pump
C)highway
D)end

Question 23

A QRS complex with one positive deflection followed by one negative deflection would be labeled

A)RS.
B)QS.
C)QR.
D)RR'.

Question 24

A beat that appears on the rhythm strip after a long pause and causes a slower rhythm than the normal rhythm is called a(n)

A)usurpation beat.
B)irritable beat.
C)escape beat.
D)pacemaker beat.

Question 25

The ventricle's inherent rate is

A)20-40 beats per minute.
B)40-60 beats per minute.
C)60-80 beats per minute.
D)60-100 beats per minute.

Question 26

The job of the cardiac conduction system's pacemaker is to

A)propagate electrical impulses.
B)conduct electrical impulses.
C)cause depolarization of myocardial cells.
D)all of the above.

Question 27

The PR interval would be considered abnormal if it measured ________ small blocks on the EKG paper.

A)3
B)4
C)5
D)6

Question 28

A QRS complex that has both an R and an R' wave will have

A)one positive deflection.
B)two positive deflections.
C)one negative deflection.
D)two negative deflections.

Question 29

After the sinus node initiates an impulse,where does the impulse go next?

A)Interatrial tracts
B)Purkinje fibers
C)Ventricular tissue
D)Bundle branches

Question 30

On a rhythm strip,the P wave is normally

A)spiked.
B)small.
C)inverted.
D)last.

Question 31

The electrical impulse travels through the ________ to get from the atrium to the AV node.

A)interatrial tracts
B)bundle of His
C)Purkinje fibers
D)internodal tracts

Question 32

Contractility is the ability of a cardiac cell to

A)initiate an impulse without outside stimulus.
B)pass an impulse along to neighboring cells.
C)respond to a stimulus by depolarizing.
D)contract.

Question 33

The normal inherent rate of the sinus node as a pacemaker is

A)20-40 beats per minute.
B)40-60 beats per minute.
C)60-80 beats per minute.
D)60-100 beats per minute.

Question 34

An upward deflection of the QRS complex is called a(n)

A)P wave.
B)Q wave.
C)R wave.
D)T wave.

Question 35

The area of the conduction system that initiates the impulse is called the

A)internodal tract.
B)pacemaker.
C)bundle of His.
D)lead.

Question 36

The normal pacemaker of the heart is the

A)sinus node.
B)AV node.
C)Purkinje fibers.
D)coronary sinus.

Question 37

On EKG paper,one big block represents

A)0.04 sec.
B)0.10 sec.
C)0.20 sec.
D)1 sec.

Question 38

What is TRUE about the following intervals: PR 0.14,QRS 0.08?

A)The QRS interval is prolonged.
B)PR interval is shortened.
C)PR interval is prolonged.
D)Intervals are normal.

Question 39

If a pacemaker becomes irritable and fires at a faster than normal rate,________ will occur.

A)escape
B)usurpation
C)cardiac block
D)refraction

Question 40

Which of these statements about the sinus node is FALSE?

A)It is the normal pacemaker of the heart.
B)It has the fastest inherent rate of all the possible pacemaker sites.
C)It is the slowest pacemaker of the heart.
D)It fires at an inherent rate of 60-100 beats per minute.

Question 41

The normal rate of the sinus node is 60-100 beats per minute.

Question 42

The EKG is a recording of the

A)heart's mechanical activity.
B)brain's electrical activity.
C)heart's electrical activity.
D)heart's electrical and mechanical activity.

Question 43

If a heart rhythm is slower than normal,it is called a(n)

A)arrhythmia.
B)plateau.
C)complex.
D)deflection.

Question 44

The cardiac cell,at rest,has a transmembrane potential of +20 mV.

Question 45

The PR interval measures the time it takes for the impulse to travel from the

A)AV node to the bundle branches.
B)bundle of His to the ventricular myocardium.
C)sinus node to the internodal tracts.
D)atria to the ventricle.

Question 46

Cardiac cell stimulus during the absolute refractory period often results in very fast,dangerous rhythms.

Question 47

The ST segment is a flat line from which the waves and complexes take off.

Question 48

If the sinus node and atria both fail,the ________ will be absent on the rhythm strip.

A)P wave
B)QRS complex
C)R wave
D)T wave

Question 49

The PR interval measures the time it takes for the impulse to travel from the atrium down to the ventricle.

Question 50

If the PR interval is 0.10 secs,the time it takes for the impulse to travel from the atrium down to the ventricle is abnormal.

Question 51

Atrial depolarization is represented on the EKG as a ________.

Question 52

The PR segment is a flat line located between the QRS complex and the T wave.

Question 53

The P wave represents atrial depolarization.

Question 54

If the sinus node,atria,and AV node all fail,the heart rate will be between

A)40 to 60 beats per minute.
B)20 to 40 beats per minute.
C)10 to 20 beats per minute.
D)60 to 100 beats per minute.

Question 55

The job of the cardiac conduction system is to

A)propagate electrical impulses.
B)conduct electrical impulses.
C)cause depolarization of myocardial cells.
D)all of the above.

Question 56

During the absolute refractory period,only a strong stimulus can result in depolarization.

Question 57

The polarized cardiac cell is electrically negative.

Question 58

The baseline is a flat line from which the waves and complexes take off.

Question 59

The normal pacemaker of the heart is the AV node.

Question 60

Depolarization is the changing of the cardiac cell to an electrically ________ charge.

Question 61

Refractory means ________ to.

Question 62

Normal QRS interval is ________ seconds or less than three small blocks.

Question 63

One small block on the EKG paper measures ________ seconds.

Question 64

The pacemaker with the slowest inherent rate is the ________.

Question 65

Transmembrane potential is the electrical charge at the ________.

Question 66

A negative deflection that occurs before a positive one is labeled a ________ wave.

Question 67

Normal conduction begins with the pacemaker of the heart,the ________.

Question 68

Arrhythmias are ________ heart rhythms.