#1
Which structure in the heart is responsible for initiating the electrical signal for the heartbeat?
Atrioventricular (AV) node
Sinoatrial (SA) node
Bundle of His
Purkinje fibers
#2
What is the term for the brief period of electrical silence that occurs before the atria contract during the cardiac cycle?
P-R interval
T wave
QT interval
P-R segment
#3
Which ion plays a key role in depolarization during the cardiac action potential?
Sodium (Na+)
Potassium (K+)
Calcium (Ca2+)
Chloride (Cl-)
#4
Which part of the electrocardiogram (ECG or EKG) represents the depolarization of the atria?
P wave
QRS complex
T wave
U wave
#5
What is the primary role of the Sinoatrial (SA) node in the cardiac conduction system?
Conducting electrical signals to the atria
Initiating the electrical signal for the heartbeat
Delaying the electrical signal to allow the atria to contract before the ventricles
Conducting electrical signals to the ventricles
#6
What is the main function of the atrioventricular (AV) node in the cardiac conduction system?
Conducting electrical signals to the atria
Delaying the electrical signal to allow the atria to contract before the ventricles
Initiating the electrical signal for the heartbeat
Conducting electrical signals to the ventricles
#7
Which term describes the time taken for the heart to go through one complete cardiac cycle, including contraction and relaxation?
Cardiac output
Stroke volume
Cardiac cycle
Heart rate
#8
In the cardiac conduction system, what does the term 'repolarization' refer to?
Relaxation of the heart muscle
Restoration of the resting membrane potential after depolarization
Conduction of electrical signals to the ventricles
Initiation of the electrical signal for the heartbeat
#9
Which part of the heart's conduction system is responsible for the rapid transmission of the electrical impulse to the myocardial cells?
Bundle of His
Sinoatrial (SA) node
Purkinje fibers
Atrioventricular (AV) node
#10
What is the term for the phase in the cardiac action potential when the cell membrane becomes more negative and returns to its resting state?
Depolarization
Repolarization
Hyperpolarization
Resting phase
#11
Which cardiac conduction system component is responsible for conducting electrical signals from the atria to the ventricles?
Sinoatrial (SA) node
Bundle of His
Atrioventricular (AV) node
Purkinje fibers
#12
In the cardiac conduction system, what is the role of the Bundle of His?
Initiating the electrical signal for the heartbeat
Delaying the electrical signal to allow the atria to contract before the ventricles
Conducting electrical signals to the atria
Conducting electrical signals to the ventricles
#13
Which electrocardiogram (ECG or EKG) wave represents the depolarization of the ventricles?
P wave
QRS complex
T wave
U wave
#14
What is the normal range for the duration of the QRS complex on an electrocardiogram (ECG or EKG)?
Less than 0.10 seconds
0.12 to 0.20 seconds
0.20 to 0.30 seconds
More than 0.30 seconds
#15
Which physiological event corresponds to the T wave on an electrocardiogram (ECG or EKG)?
Atrial depolarization
Ventricular depolarization
Ventricular repolarization
Atrial repolarization
#16
During which phase of the cardiac cycle does ventricular filling occur?
Isovolumetric contraction
Ventricular ejection
Isovolumetric relaxation
Atrial systole
#17
What is the primary function of the Purkinje fibers in the heart's conduction system?
Initiating the electrical signal for the heartbeat
Delaying the electrical signal to allow the atria to contract before the ventricles
Conducting electrical signals to the atria
Conducting electrical signals to the ventricles