#1
Which structure initiates the electrical impulse in the heart?
Sinoatrial (SA) node
ExplanationThe SA node generates the heart's electrical impulse.
#2
What is the function of the atrioventricular (AV) node in the heart's conduction system?
To delay the impulse briefly before it travels to the ventricles
ExplanationThe AV node briefly delays the impulse before transmitting it to the ventricles.
#3
What is the normal resting heart rate, primarily set by the SA node?
60-80 beats per minute
ExplanationThe SA node sets the normal resting heart rate between 60-80 beats per minute.
#4
Which part of the heart's conduction system is responsible for transmitting the electrical signal from the atria to the ventricles?
Bundle of His
ExplanationThe Bundle of His transmits the electrical signal from the atria to the ventricles.
#5
What is the role of the Purkinje fibers in the heart's conduction system?
To distribute the impulse rapidly throughout the ventricles
ExplanationPurkinje fibers distribute the impulse rapidly throughout the ventricles.
#6
Which structure connects the atria to the ventricles and is responsible for transmitting the electrical impulse?
Bundle of His
ExplanationThe Bundle of His connects the atria to the ventricles and transmits the electrical impulse.
#7
Which of the following is NOT part of the intrinsic conduction system of the heart?
Coronary arteries
ExplanationCoronary arteries are not part of the heart's intrinsic conduction system.
#8
What is the sequence of electrical conduction through the heart?
SA node → AV node → Bundle of His → Purkinje fibers
ExplanationThe sequence of conduction starts from the SA node, goes through the AV node, Bundle of His, and finally, to Purkinje fibers.
#9
Which of the following is true regarding the Bundle of His?
It branches into Purkinje fibers to distribute the impulse throughout the ventricles
ExplanationThe Bundle of His branches into Purkinje fibers to distribute the impulse to the ventricles.
#10
What happens if the SA node fails to function properly?
The AV node will take over as the primary pacemaker
ExplanationIf the SA node fails, the AV node will become the primary pacemaker of the heart.
#11
Which component of the intrinsic conduction system is also known as the pacemaker of the heart?
Sinoatrial (SA) node
ExplanationThe SA node, or sinoatrial node, is the pacemaker of the heart.
#12
What is the primary function of the atrioventricular (AV) node?
To delay the impulse briefly before it is transmitted to the ventricles
ExplanationThe AV node primarily delays the impulse before transmitting it to the ventricles.
#13
Which part of the heart's conduction system is responsible for transmitting the impulse to the ventricles?
Bundle of His
ExplanationThe Bundle of His transmits the impulse to the ventricles.
#14
What is the term for an abnormally fast heart rhythm (>100 beats per minute) originating from the SA node?
Sinus tachycardia
ExplanationSinus tachycardia is an abnormally fast heart rhythm originating from the SA node.
#15
What effect does sympathetic stimulation have on the heart's conduction system?
Increases heart rate and conduction velocity
ExplanationSympathetic stimulation increases heart rate and conduction velocity.
#16
What is the name of the condition where there is a delay or interruption in the electrical impulses between the atria and ventricles?
Heart block
ExplanationHeart block is a condition characterized by a delay or interruption in electrical impulses between the atria and ventricles.
#17
Which of the following is a disorder characterized by a chaotic, irregular heartbeat due to rapid, uncoordinated electrical signals in the atria?
Atrial fibrillation
ExplanationAtrial fibrillation is a disorder characterized by rapid, uncoordinated electrical signals in the atria.
#18
Which of the following is a condition characterized by an abnormally slow heart rate (<60 beats per minute) due to a malfunction in the SA node?
Sinus bradycardia
ExplanationSinus bradycardia is a condition characterized by an abnormally slow heart rate due to a malfunction in the SA node.