Anatomy 2 Heart Electrical Activity/Cardiac Cycle

When ventricular pressure becomes greater than atrial pressure

At what point during the cardiac cycle does the AV valve close? a. When ventricular pressure becomes greater than aortic pressure b. When the semilunar valve opens c. When aortic pressure becomes greater than ventricular pressure d. When ventricular pressure becomes greater than atrial pressure

When atrial pressure becomes greater than ventricular pressure

At what point in the cardiac cycle does the AV valve open? a. When aortic pressure becomes greater than ventricular pressure b. When ventricular pressure becomes greater than aortic pressure c. When the semilunar valve closes d. When atrial pressure becomes greater than ventricular pressure

When pressure in the ventricle becomes less than aortic pressure

At what point in the cardiac cycle does the semilunar valve close? a. When ventricular pressure becomes greater than aortic pressure b. When pressure in the ventricle becomes less than aortic pressure c. When ventricular pressure becomes greater than atrial pressure d. When atrial pressure becomes greater than ventricular pressure

When ventricular pressure becomes greater than aortic pressure

At what point in the cardiac cycles does the semilunar valve open? a. When atrial pressure becomes greater than ventricular pressure b. When the AV valve closes c. When ventricular pressure becomes greater than atrial pressure d. When ventricular pressure becomes greater than aortic pressure

Atrial contraction

Atrial pressure is greater than ventricular pressure during which phase of the cardiac cycle? a. Ventricular ejection b. Isovolumetric contraction c. Atrial contraction d. Isovolumetric relaxation

Semilunar valves are open

During the ventricular ejection phase of the cardiac cycle, which of the following is true? a. Ventricles are in diastole b. Semilunar valves are open c. AV valves are open d. Atria are in systole

P wave

Contraction of the atria is triggered by electrical activity that is recorded on the ECG tracing as the ________. a. T wave b. QRS complex c. P wave d. A wave

Pressure in the atria would be greater than pressure in the ventricles

Describe the pressures in the atria and ventricles that would cause the opening of the AV valves. a. Pressure in the ventricles would be greater than in the atria b. Pressures in the atria and ventricles would be equal c. Pressure in the atria would be greater than pressure in the ventricles

Pacemaker cells are able to stimulate action potentials in the cardiac contractile cells

How does the presence of pacemaker cells affect the electrical activity of the cardiac contractile cells? a. Pacemaker cells are able to stimulate action potentials in the cardiac contractile cells b. Pacemaker cells increase the frequency of normally occurring action potentials in the cardiac contractile cells c. Activity of pacemaker cells cancels out action potentials of cardiac contractile cells

From a region of high pressure to a region of low pressure

In what direction does blood flow through the heart? a. From a region of high oxygen content to a region of low oxygen content b. From ventricles to atria c. From a region of high pressure to a region of low pressure d. From a region of high volume to a region of low volume

AV valves only

Increased pressure in the ventricles would close what valve(s)? a. AV valves only b. Both semilunar and AV valves c. Semilunar valves only

Ventricular diastole

Isovolumetric relaxation and ventricular filling take place during ________. a. Ventricular diastole b. Ventricular systole

The semilunar and AV valves are closed

Isovolumetric relaxation is characterized by which of the following? a. Blood flows backward through the heart from high to low pressure b. The semilunar and AV valves are closed c. Pressure in the atrium exceeds pressure in the ventricle d. Pressure in the ventricle exceeds pressure in the aorta

Ventricular ejection

Most of the decrease in ventricular volume takes place during which phase of the cardiac cycle? a. Isovolumetric relaxation b. Ventricular ejection c. Atrial contraction d. Ventricular filling

Atrial contraction

Most of the increase in left ventricular volume takes place during which phase of the cardiac cycle? a. Atrial contraction b. Ventricular filling c. Ventricular ejection d. Isovolumetric relaxation

Isovolumetric contraction, ventricular ejection, isovolumetric relaxation

Put the phases of the cardiac cycle in the correct order, starting after ventricular filling. a. Isovolumetric contraction, ventricular ejection, isovolumetric relaxation b. Ventricular ejection, ventricular relaxation, isovolumetric contraction c. Isovolumetric relaxation, ventricular ejection, isovolumetric contraction d. Ventricular ejection, isovolumetric contraction, isovolumetric relaxation

Pacemaker cells

The specialized cardiac cells of the SA node are most precisely known as ________. a. Intrinsic cells b. Atrial cells c. Pacemaker cells d. Contractile cells

Ventricular ejection

Ventricular pressure is greater than aortic pressure during which phase of the cardiac cycle? a. Ventricular ejection b. Isovolumetric relaxation c. Ventricular filling d. Isovolumetric contraction

Greater pressure in the aorta than in the left ventricle

What causes the aortic semilunar valve to close? a. Greater pressure in the aorta than in the left ventricle b. Higher ventricular pressure than aortic pressure c. Equal ventricular and aortic pressures

To prevent backward flow of blood

What is the main function of heart valves? a. To pump blood through the heart b. To prevent backward flow of blood c. To separate the left and right atria d. To separate the atria and ventricles

The ventricles are in diastole

When the atria contract, which of the following is true? a. The atria are in diastole b. The ventricles are in diastole c. The semilunar valves are open d. The AV valves are closed

Action potentials are delayed at the AV node

Which of the following characteristics of the intrinsic conduction system best explains why atrial contraction finishes before ventricular contraction begins? a. Pacemaker cells are autorhythmic b. Purkinje fibers have the slowest rate of spontaneous depolarization c. The SA node initiates electrical impulses d. Action potentials are delayed at the AV node

AV bundle

Which of the following functions as the electrical connection between the atria and ventricles? a. AV bundle b. SA node c. AV node d. Purkinje fibers

Most blood flows passively into the ventricles through open AV valves

Which of the following is correct about the filling of the ventricles? a. The majority of ventricular filling is caused by contraction of the atria b. Most blood flows passively into the ventricles through open AV valves

EDV

Which of the following is equivalent to the ventricular volume during isovolumetric contraction? a. ESV b. SV c. EDV d. MVV

ESV

Which of the following is equivalent to the ventricular volume during isovolumetric relaxation? a. EDV b. ESV c. SV d. MVV

AV valves are closed

Which of the following is true during ventricular systole? a. AV valves are closed b. Atria are in systole c. Ventricles are relaxed d. Ventricles are empty

SA node

Which part of the intrinsic conduction system initiates the depolarizing impulse and normally sets the pace for the entire heart? a. AV bundle b. SA node c. Purkinje fibers d. AV node