#1
Which structure is responsible for initiating the heartbeat in the heart?
Sinoatrial node (SA node)
ExplanationThe SA node initiates the heartbeat by generating electrical impulses.
#2
Which part of the heart's conduction system is known as the 'pacemaker'?
Sinoatrial node (SA node)
ExplanationThe SA node, known as the pacemaker, sets the rhythm for the heart's contractions.
#3
What is the normal resting heart rate range for adults?
60-80 beats per minute
ExplanationThe normal resting heart rate for adults falls within the range of 60 to 80 beats per minute.
#4
What is the term for a condition where the heart's electrical impulse formation or conduction is impaired, leading to irregular heartbeats?
Arrhythmia
ExplanationArrhythmia is a condition involving irregular heartbeats due to impaired impulse formation or conduction.
#5
What is the term for the condition where the heart rate is persistently above the normal range?
Tachycardia
ExplanationTachycardia is a condition characterized by a persistently elevated heart rate above the normal range.
#6
What is the function of the bundle of His in the heart?
To conduct electrical signals from the AV node to the ventricles
ExplanationThe bundle of His conducts electrical signals from the AV node to the ventricles, coordinating heart contractions.
#7
Which part of the heart's electrical conduction system is responsible for transmitting impulses rapidly throughout the ventricles?
Purkinje fibers
ExplanationPurkinje fibers transmit impulses quickly, ensuring rapid and synchronized ventricular contractions.
#8
Which wave in an electrocardiogram (ECG/EKG) represents atrial depolarization?
P wave
ExplanationThe P wave signifies atrial depolarization, initiating the contraction of the atria.
#9
Which part of the heart's electrical conduction system delays impulses to allow the atria to contract before the ventricles?
Atrioventricular node (AV node)
ExplanationThe AV node delays impulses, ensuring coordinated contraction by allowing the atria to contract before the ventricles.
#10
Which segment of an electrocardiogram (ECG/EKG) represents the time it takes for the electrical impulse to travel from the atria to the ventricles?
PR interval
ExplanationThe PR interval on an ECG represents the time for the electrical impulse to travel from the atria to the ventricles.
#11
What happens during the ST segment of an electrocardiogram (ECG/EKG)?
Ventricular repolarization
ExplanationThe ST segment represents ventricular repolarization, preparing the heart for the next contraction.
#12
Which electrolyte imbalance can lead to significant disturbances in the heart's electrical conduction system?
Hyperkalemia (high potassium)
ExplanationHyperkalemia, or high potassium levels, can disrupt the heart's electrical conduction system.
#13
What term is used to describe a complete cessation of electrical activity in the heart?
Asystole
ExplanationAsystole refers to a complete cessation of electrical activity in the heart, leading to cardiac arrest.
#14
Which phase of the cardiac action potential is characterized by rapid depolarization of the ventricular cells?
Phase 0
ExplanationPhase 0 of the cardiac action potential involves rapid depolarization of the ventricular cells, initiating the electrical activity.
#15
What is the term for the abnormal electrical conduction pathway that bypasses the atrioventricular node?
Wolff-Parkinson-White syndrome
ExplanationWolff-Parkinson-White syndrome is characterized by an abnormal electrical conduction pathway bypassing the AV node.