What is the equation relating stroke volume (SV), end-diastolic volume (EDV), and end-stroke volume (ESV)?
  • Sinoatrial node and atrioventricular node.
  • Decreased end-diastolic volume.
  • SV = EDV - ESV (Stroke volume equation).
  • It occurs at the same time as the QRS complex.
Which component of an ECG represents ventricular depolarization?
  • Q-T interval.
  • The applied current depolarizes all the muscles cells at the same time, returning synchronus electrical activity to the heart.
  • QRS complex.
  • CO = HR x SV.
An increase in venous return would result in a(n) ____.
  • Increased end-diastolic volume.
  • Heart rate and stroke volume.
  • Generate its own contractile cycle.
  • Increase in parasympathetic activity.
During isovolumetric relaxation, _____.
  • The rate of spontaneous depolarization in SA nodal cells decreases.
  • Only potassium permeability is increased.
  • To permit blood to flow forward while preventing it from flowing backward.
  • The AV and semilunar valves are closed and ventricular pressure is decreasing.
Which component of an ECG represents ventricular diastole?
  • P-R interval.
  • T-wave.
  • T-Q segment.
  • 120 beats/min.
Which of the following factors determines preload?
  • Heart rate and stroke volume.
  • Heart rate and venous retum.
  • Ventricular pressure is less than aortic pressure.
  • Decreased end-diastolic volume.
A decrease in afterload will lead to which of the following?
  • Increased stroke volume.
  • Increased volume of blood in the aorta.
  • Atrial depolarization.
  • Decreased end-diastolic volume.
The increased aortic pressure that occurs during systole reflects a(n) _____.
  • Increased end-diastolic volume.
  • Sinoatrial node and atrioventricular node.
  • Decreased end-diastolic volume.
  • Increased volume of blood in the aorta.
Which of the following is NOT a part of the excitation-contraction coupling in cardiac muscle?
  • Calcium binds to calmodulin in the cytosol.
  • Hormonal stimulation.
  • SA Node, AV Node, bundle of His, bundle branches, and Purkinje fibers.
  • QRS complex.
Which of the following is TRUE of the ventricular filling phase of the cardiac cycle?
  • Ventricular pressure is less than aortic pressure.
  • Decreased end-diastolic volume.
  • Type T calcium channels.
  • Ventricular ejection.
The preload is approximately the same as the ________ pressure.
  • End-diastolic.
  • Stroke volume.
  • QRS complex.
  • P-R interval.
Given end-diastolic volume = 130 mL and end-systolic volume = 50 mL, what is the stroke volume and ejection fraction?
  • SV = 80 mL, EF = 0.61
  • SV = EDV - ESV (Stroke volume equation).
  • Type T calcium channels.
  • Isovolumetric relaxation.
Which of the following components of an ECG represents ventricular repolarization?
  • T-wave.
  • Afterload.
  • P-wave.
  • The rate of spontaneous depolarization in SA nodal cells decreases.
What is occurring during ventricular ejection?
  • Sinoatrial node and atrioventricular node.
  • The AV valves are closed and the semilunar valves are open as blood is leaving the ventricles.
  • Heart rate and venous retum.
  • Heart rate and stroke volume.
Cardiac output is determined by what two variables?
  • Heart rate and stroke volume.
  • Increased stroke volume.
  • Sympathetic and parasympathetic nervous systems.
  • Generate its own contractile cycle.
Which of the following decreases heart rate?
  • Potassium channel closing is enhanced.
  • Decreased end-diastolic volume.
  • Increase in parasympathetic activity.
  • Heart rate and venous retum.
What component of the conduction pathway transmits the action potential to the ventricular contractile cells?
  • Of ventricular diastole.
  • Purkinje Fibers.
  • P-R interval.
  • Q-T interval.
What two major regions of the heart contain a concentration of pacemaker cells?
  • SA Node, AV Node, bundle of His, bundle branches, and Purkinje fibers.
  • Sinoatrial node and atrioventricular node.
  • Increased volume of blood in the aorta.
  • Generate its own contractile cycle.
In what phase is the cardiac cycle when the AV valves are open and semilunar valves are closed?
  • Ventricular filling.
  • Ventricular ejection.
  • Isovolumetric relaxation.
  • Of ventricular diastole.
The SA node is innervated by the ____.
  • Heart rate and venous retum.
  • Heart rate and stroke volume.
  • Sympathetic and parasympathetic nervous systems.
  • Sinoatrial node and atrioventricular node.
Which of the following structures is poorly innervated by the parasympathetic nervous system and, therefore, an increase in parasympathetic activity has little effect on this structure?
  • Ventricles.
  • Extrinsic.
  • P-wave.
  • T-wave.
The rapid depolarization phase of a pacemaker cell action potential is caused by movement of _____.
  • Potassium channel closing is enhanced.
  • The time of ventricular systole.
  • Increased volume of blood in the aorta.
  • Calcium through the L-type channels.
What is the primary function of the AV and semilunar valves?
  • Sinoatrial node and atrioventricular node.
  • Remove calcium from the cytosol by transporting it to the extracellular fluid thereby relaxing the muscle.
  • To permit blood to flow forward while preventing it from flowing backward.
  • SV = EDV - ESV (Stroke volume equation).
In an ECG recording, the RR interval is 0.5 seconds. What is the heart rate?
  • Stroke volume.
  • P-R interval.
  • 120 beats/min.
  • Ventricular ejection.
Which of the following variables is NOT an intrinsic factor that alters cardiac function?
  • Hormonal stimulation.
  • Type T calcium channels.
  • Afterload.
  • Potassium channel closing is enhanced.
What causes the sounds that one hears as the heart beats?
  • SV = EDV - ESV (Stroke volume equation).
  • The AV valves are closed and the semilunar valves are open as blood is leaving the ventricles.
  • The turbulence created as the valves close.
  • Sodium movement into the cell.
The volume of blood ejected from the ventricle with each contraction can be described by the equation _____.
  • Sinoatrial node and atrioventricular node.
  • (End-diastolic volume) - (End-systolic volume).
  • The amount of time between heartbeats.
  • Isovolumetric relaxation.
In what phase is the cardiac cycle when all four valves are closed and pressure in the ventricle is decreasing?
  • Purkinje Fibers.
  • Type T calcium channels.
  • Isovolumetric relaxation.
  • Ventricular ejection.
Whereas the contractile activity of skeletal muscle is called ________, that of cardiac muscle is ________ because the contraction originates within the musculature itself.
  • Neurogenic ; myogenic.
  • Ventricles.
  • Isovolumetric contraction.
  • Of ventricular diastole.
Closure of the atrioventricular valve occurs when _____.
  • Calcium binds to calmodulin in the cytosol.
  • Potassium channel closing is enhanced.
  • Pressure inside the ventricle is greater than pressure inside the atrium.
  • A decrease in parasympathetic activity and an increase in sympathetic activity.
Which of the following components of an ECG represents atrial depolarization?
  • QRS complex.
  • T-wave.
  • The rate of spontaneous depolarization in SA nodal cells decreases.
  • P-wave.
Under resting conditions, heart rate is primarily under the control of what control system?
  • It occurs at the same time as the QRS complex.
  • The amount of time between heartbeats.
  • The parasympathetic nervous system.
  • The time of ventricular systole.
Which of the following is an effect of parasympathetic activity to the heart?
  • The rate of spontaneous depolarization in SA nodal cells decreases.
  • Ventricular pressure is less than aortic pressure.
  • Calcium binds to calmodulin in the cytosol.
  • Potassium channel closing is enhanced.
An increase in heart rate can be mediated through which of the following?
  • A decrease in parasympathetic activity and an increase in sympathetic activity.
  • Pressure in the pulmonary artery is greater than pressure in the right ventricle.
  • Increased end-diastolic volume.
  • Increased stroke volume.
The opening and closure of the atrioventricular and semilunar valves is driven by _____.
  • Potassium channel closing is enhanced.
  • Calcium through the L-type channels.
  • Differences in pressure across the valve.
  • Increased volume of blood in the aorta.
Which component of an ECG represents the AV nodal conduction time?
  • P-R interval.
  • T-Q segment.
  • QRS complex.
  • Purkinje Fibers.
The volume of blood that is pumped by the heart every minute is determined by the equation
  • QRS complex.
  • Potassium ; funny
  • Hormonal stimulation.
  • CO = HR x SV.
The second heart sound coincides with the beginning of which period in the cardiac cycle?
  • Isovolumetric relaxation.
  • Hormonal stimulation.
  • Differences in pressure across the valve.
  • Calcium through the L-type channels.
What phase of the cardiac cycle is the heart in when all four valves of the heart are closed and ventricular pressure is building, but is not yet great enough to open a valve?
  • Ventricular ejection.
  • Of ventricular diastole.
  • Isovolumetric relaxation.
  • Isovolumetric contraction.
What causes the rapid depolarization phase of a contractile cell action potential?
  • Sodium movement into the cell.
  • The time of ventricular systole.
  • Isovolumetric relaxation.
  • SV = EDV - ESV (Stroke volume equation).
Which of the following variables is NOT involved in determining ventricular preload?
  • Calcium binds to calmodulin in the cytosol.
  • Afterload.
  • Heart rate and venous retum.
  • P-wave.
The end-diastolic volume minus the end-systolic volume is the _____.
  • Stroke volume.
  • P-R interval.
  • Potassium ; funny
  • Increased volume of blood in the aorta.
The rapid depolarization phase of the action potential in the pacemaker cells is driven by the rapid influx of ________ ions through ________ channels.
  • Atrial contraction.
  • Calcium ; L-type.
  • Stroke volume.
  • Purkinje Fibers.
The R-R interval is the time between the peaks of two successive QRS complexes and represents ____.
  • Calcium through the L-type channels.
  • The parasympathetic nervous system.
  • Generate its own contractile cycle.
  • The amount of time between heartbeats.
The small increase in ventricular pressure observed late in diastole is caused by _____.
  • Atrial contraction.
  • Ventricular ejection.
  • The time of ventricular systole.
  • Atrial depolarization.
Which of the following is a FALSE statement about sympathetic activity to the SA node?
  • Potassium channel closing is enhanced.
  • Ventricular pressure is less than aortic pressure.
  • The rate of spontaneous depolarization in SA nodal cells decreases.
  • Decreased end-diastolic volume.
Which of the following components of an ECG represents ventricular depolarization?
  • Ventricles.
  • QRS complex.
  • Hormonal stimulation.
  • Potassium channel closing is enhanced.
The Q-T interval is the time from the onset of the QRS complex to the end of the T wave which measures
  • The time of ventricular systole.
  • The rate of spontaneous depolarization in SA nodal cells decreases.
  • The amount of time between heartbeats.
  • Differences in pressure across the valve.
Conduction through which of the following is slow to allow atria to contract before the ventricles?
  • P-wave.
  • AV Node.
  • T-wave.
  • Afterload.
In what phase of the cardiac cycle does ventricular pressure exceed aortic pressure?
  • Ventricles.
  • Ventricular ejection.
  • Isovolumetric contraction.
  • Isovolumetric relaxation.
Which component of an ECG represents ventricular repolarization?
  • T-Q segment.
  • T-wave.
  • QRS complex.
  • P-wave.
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