Recent

  • Show all results for ""
Cardiac Cycle Overview Quiz
37 Questions
0 Views

Cardiac Cycle Overview Quiz

Created by
@VeritableJadeite

Questions and Answers

What happens to ventricular pressure at the end of systole?

  • It increases rapidly due to blood flow from the atria.
  • It decreases rapidly back to low diastolic levels. (correct)
  • It remains constant until the aortic valve closes.
  • It fluctuates due to continuous atrial contractions.

    • What occurs at the beginning of isovolumic relaxation?

  • Ventricular repolarization is complete. (correct)
  • Atrial pressure exceeds ventricular pressure.
  • Blood flows backward into the ventricles.
  • Ventilation rates in the lungs increase.

    • Which event indicates the end of the isovolumic relaxation phase?

  • The ventricles reaching their maximum volume.
  • The appearance of the P wave on the ECG. (correct)
  • The start of atrial systole.
  • The closure of the aortic valve.

    • What is observed in the phonogram during isovolumic relaxation?

    <p>Silence with no recorded heart sound.</p> Signup and view all the answers

    How does left atrial pressure compare to left ventricular pressure during diastole?

    <p>Left atrial pressure is slightly higher than left ventricular pressure.</p> Signup and view all the answers

    What occurs at the beginning of the ventricular contraction phase?

    <p>Ventricular pressures rapidly rise.</p> Signup and view all the answers

    What remains unchanged during reduced ventricular ejection?

    <p>Ejection volume.</p> Signup and view all the answers

    When does the first heart sound (S1) occur in relation to the QRS complex?

    <p>Simultaneously with the peak of the R wave.</p> Signup and view all the answers

    Which of the following statements is true about blood flow during the last two-thirds of the ejection phase?

    <p>30% of available blood volume flows out.</p> Signup and view all the answers

    What happens to ventricular pressure at the end of the ejection phase?

    <p>It falls below aortic pressure.</p> Signup and view all the answers

    What initiates the closure of the mitral and tricuspid valves?

    <p>A rapid rise in ventricular pressure.</p> Signup and view all the answers

    What drives the continued flow of blood after the pump has stopped?

    <p>Inertia of the blood.</p> Signup and view all the answers

    How does ventricular volume change during the slow ejection phase?

    <p>It remains unchanged.</p> Signup and view all the answers

    Which sequence correctly traces the path of an action potential in the heart?

    <p>Superior vena cava → both atria → A-V bundle → ventricles</p> Signup and view all the answers

    What role do the atria serve in the cardiac cycle?

    <p>They act as primer pumps for the ventricles.</p> Signup and view all the answers

    What is the significance of the 0.1 second delay when passing the cardiac impulse from atria to ventricles?

    <p>It allows atrial contraction to complete before ventricular contraction begins.</p> Signup and view all the answers

    During the cardiac cycle, which of the following is NOT a characteristic of the ventricles?

    <p>They initiate the electrical impulse for cardiac contraction.</p> Signup and view all the answers

    Which of the following best describes the cardiac cycle?

    <p>A sequence of cardiac events from one heartbeat to another.</p> Signup and view all the answers

    What happens to the blood in the ventricles during a strong ventricular contraction?

    <p>Blood is pumped into the aorta and pulmonary artery.</p> Signup and view all the answers

    What component of the heart sequence represents the 'pacemaker'?

    <p>The sinus node</p> Signup and view all the answers

    What is primarily illustrated by the Wiggers diagram in relation to the cardiac cycle?

    <p>The relationship between pressure, volume, and electrical activity in the heart.</p> Signup and view all the answers

    What causes the second heart sound?

    <p>Closure of semilunar valves</p> Signup and view all the answers

    What does the dicrotic notch on the aortic pressure represent?

    <p>Closure of aortic valve</p> Signup and view all the answers

    During which phase of the cardiac cycle is aortic pressure highest?

    <p>Reduced ventricular ejection</p> Signup and view all the answers

    What does the P wave of the ECG represent?

    <p>Atrial depolarization</p> Signup and view all the answers

    What volume of blood is typically pumped out by each ventricle during a cardiac cycle?

    <p>120 ml</p> Signup and view all the answers

    Atrial systole is preceded by which electrical event?

    <p>p-wave</p> Signup and view all the answers

    Which statement about ventricular systole is false?

    <p>The ventricles relax</p> Signup and view all the answers

    What happens during the isovolumic contraction phase?

    <p>The pressure in the ventricles increases without a change in volume</p> Signup and view all the answers

    What primarily causes the opening of the mitral valve during rapid ventricular filling?

    <p>Ventricular pressure becoming less than atrial pressure</p> Signup and view all the answers

    During which phase does the third heart sound (S3) typically occur?

    <p>At the end of rapid ventricular filling</p> Signup and view all the answers

    What happens to the ventricular volume during the diastasis phase?

    <p>It slowly rises and then plateaus</p> Signup and view all the answers

    What is the ejection fraction typically considered to be during rapid ventricular filling?

    <p>0.6/60%</p> Signup and view all the answers

    What leads to a gradual drop in aortic pressure during rapid ventricular filling?

    <p>Closure of the aortic valve</p> Signup and view all the answers

    What is characteristic of the ECG during the rapid ventricular filling phase?

    <p>No electrical activity visible</p> Signup and view all the answers

    In which phase does only a small amount of blood enter the ventricles?

    <p>Diastasis</p> Signup and view all the answers

    What is the relationship between atrial pressure and ventricular pressure at the start of rapid ventricular filling?

    <p>Atrial pressure is slightly higher than ventricular pressure</p> Signup and view all the answers

    Study Notes

    Cardiac Cycle Overview

    • The cardiac cycle comprises a sequence of mechanical and electrical events repeating with each heartbeat.
    • Initiated by an action potential from the sinoatrial (SA) node, functioning as the heart's pacemaker.
    • The impulse travels from the superior vena cava, stimulates both atria, and then transmits through the A-V bundle to the ventricles.
    • A 0.1-second delay in impulse transmission allows atrial contraction to precede ventricular contraction.

    Atria and Ventricles

    • Atria serve as primer pumps, sending blood into the ventricles before the stronger ventricular contractions occur.
    • Ventricles generate most cardiac power with a typical end-diastolic volume (EDV) of 120 ml.
    • During ejection, ventricular pressures rise above atrial pressures, opening semilunar valves while closing atrioventricular valves.

    Phases of the Cardiac Cycle

    • Isovolumic Relaxation:

      • After systole, ventricles repolarize and relax, decreasing intraventricular pressures.
      • Ventricular pressure drops below atrial pressure, causing the mitral valve to open, allowing blood to flow into the ventricles.

    • Rapid Ventricular Filling:

      • Blood rapidly fills the ventricles once the mitral valve opens, leading to a steep increase in ventricular volume.
      • Aortic pressure gradually declines as the aortic valve remains closed.
      • A third heart sound (S3) may be heard due to turbulent filling.

    • Diastasis (Slow Ventricular Filling):

      • Characterized by a slower influx of blood into the ventricles despite the mitral valve being open.
      • The ventricular volume reaches a plateau, with minimal blood flow from the left atrium to the left ventricle.

    Heart Sounds and Pressure Changes

    • The first heart sound (S1) is associated with closure of the mitral and tricuspid valves at the peak of the R wave on an ECG.
    • The second heart sound (S2) is caused by the closure of the semilunar valves.
    • The dicrotic notch on the aortic pressure graph results from the closure of the aortic valve.

    Key Cardiac Measurements

    • Ejection Fraction (EF): The fraction of end-diastolic volume ejected during each heartbeat, averaging approximately 60% (0.6).
    • Each ventricle pumps about 70 ml of blood during the cardiac cycle.
    • Atrial depolarization is represented by the P wave on an ECG.

    Phases of Cardiac Cycle Pressures

    • Aortic pressure is highest during reduced ventricular ejection.
    • Diastole is marked by increased atrial and ventricular pressures due to continuous venous return.

    Important Facts

    • The degree of ventricular filling during relaxation and rapid filling is crucial for efficient cardiac output.
    • The cardiac cycle incorporates electrical events (action potentials) and mechanical events (contractions and relaxations) to maintain blood circulation effectively.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Description

    Test your understanding of the cardiac cycle, including the roles of the atria and ventricles. Focus on the phases of the cardiac activity, starting from the SA node to the contraction mechanisms. Assess your knowledge of how electrical impulses control heart function.

    More Quizzes Like This

    Cardiac Cycle and Atrial Kick Quiz
    3 questions

    Cardiac Cycle and Atrial Kick Quiz

    Cardiac Cycle Phases Quiz
    6 questions

    Cardiac Cycle Phases Quiz

    ModernComposite avatar
    ModernComposite
    Understanding the Cardiac Cycle: Diastole, Contraction, and Relaxation
    12 questions

    Understanding the Cardiac Cycle: Diastole, Contraction, and Relaxation

    VirtuousClematis avatar
    VirtuousClematis
    Cardiac Cycle: Isovolumetric Contraction
    24 questions

    Cardiac Cycle: Isovolumetric Contraction

    HallowedAtlanta avatar
    HallowedAtlanta
    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser