#1
Which structure in the heart is known as the 'pacemaker'?
#2
What does the P wave represent in an electrocardiogram (ECG)?
#3
What is the term for the spread of electrical activation through the heart muscle, leading to contraction?
#4
What condition is characterized by an abnormally slow heart rate, typically below 60 beats per minute?
#5
What effect does acetylcholine have on the heart rate?
#6
Which component of the ECG represents the depolarization of the ventricles?
#7
Which ion is primarily responsible for the depolarization phase of cardiac action potentials?
#8
What is the normal resting membrane potential of cardiac cells in millivolts (mV)?
#9
What is the term for the period of time during which the cardiac muscle cannot be stimulated to contract again, regardless of stimulus strength?
#10
Which of the following conditions is characterized by rapid, irregular electrical impulses in the atria, leading to ineffective atrial contractions?
#11
Which part of the cardiac conduction system delays the impulse briefly before it moves on to the ventricles?
#12
Which ion plays a crucial role in initiating the depolarization of the sinoatrial (SA) node cells?
#13
Which ECG wave represents the repolarization of the ventricles?
#14
In which part of the heart does the electrical impulse travel to after leaving the AV node?
#15
What is the term for the delay between the depolarization of the atria and the depolarization of the ventricles in the cardiac conduction system?
#16
What does the QT interval represent in an electrocardiogram (ECG)?
#17
Which condition is characterized by a sudden cessation of cardiac electrical activity, leading to loss of cardiac output and consciousness?
#18
Which of the following factors can cause an increase in the action potential duration?
#19
Which phase of the cardiac action potential is associated with the rapid influx of sodium ions into the cell?
#20
What is the term for the phenomenon where cardiac muscle cells can propagate action potentials without external stimulation?
#21
Which phase of the cardiac action potential corresponds to the plateau phase?
#22
During which phase of the cardiac action potential does rapid repolarization occur?
#23
Which phase of the cardiac action potential is associated with the opening of voltage-gated calcium channels and the influx of calcium ions?
#24
Which of the following factors can influence cardiac conduction velocity?
#25