Podcast
Questions and Answers
Which of the following is the correct sequence of mechanical events in the cardiac cycle?
Which of the following is the correct sequence of mechanical events in the cardiac cycle?
During which phase of the cardiac cycle does the ventricle contract while the volume of blood remains constant?
During which phase of the cardiac cycle does the ventricle contract while the volume of blood remains constant?
What is the purpose of the atrial contraction phase in the cardiac cycle?
What is the purpose of the atrial contraction phase in the cardiac cycle?
During which phase of the cardiac cycle does the ventricle relax and the pressure in the ventricles drop, leading to the closure of the semilunar valves?
During which phase of the cardiac cycle does the ventricle relax and the pressure in the ventricles drop, leading to the closure of the semilunar valves?
Signup and view all the answers
What is the term for the minimum amount of blood in the ventricles during ventricular diastole?
What is the term for the minimum amount of blood in the ventricles during ventricular diastole?
Signup and view all the answers
During which phase of the cardiac cycle do the semilunar valves open and blood is ejected from the ventricles?
During which phase of the cardiac cycle do the semilunar valves open and blood is ejected from the ventricles?
Signup and view all the answers
During atrial contraction, the orifices of the SVC and IVC narrow due to
During atrial contraction, the orifices of the SVC and IVC narrow due to
Signup and view all the answers
What is the effect of ventricular contraction on atrial pressure?
What is the effect of ventricular contraction on atrial pressure?
Signup and view all the answers
Which event marks the beginning of ventricular relaxation?
Which event marks the beginning of ventricular relaxation?
Signup and view all the answers
What happens at the onset of ventricular relaxation?
What happens at the onset of ventricular relaxation?
Signup and view all the answers
What is the purpose of the dichroitic notch in ventricular relaxation?
What is the purpose of the dichroitic notch in ventricular relaxation?
Signup and view all the answers
What is the purpose of the atrial relaxation during ventricular diastole?
What is the purpose of the atrial relaxation during ventricular diastole?
Signup and view all the answers
During atrial systole, how much additional blood enters the ventricles?
During atrial systole, how much additional blood enters the ventricles?
Signup and view all the answers
What happens to the orifices in the atrium during atrial systole?
What happens to the orifices in the atrium during atrial systole?
Signup and view all the answers
What happens to venous return during atrial systole?
What happens to venous return during atrial systole?
Signup and view all the answers
During ventricular systole, the ventricular muscle contracts, causing the AV valves to close. What is the sound produced by this closure called?
During ventricular systole, the ventricular muscle contracts, causing the AV valves to close. What is the sound produced by this closure called?
Signup and view all the answers
What happens to the pressure in the ventricles during the ejection phase?
What happens to the pressure in the ventricles during the ejection phase?
Signup and view all the answers
During ventricular diastole, the pressure in the ventricles drops below the pressure in the atria. What causes the AV valves to open?
During ventricular diastole, the pressure in the ventricles drops below the pressure in the atria. What causes the AV valves to open?
Signup and view all the answers
What is the main factor that initiates ventricular diastole?
What is the main factor that initiates ventricular diastole?
Signup and view all the answers
What happens to the pressure in the ventricles during isovolumetric relaxation phase?
What happens to the pressure in the ventricles during isovolumetric relaxation phase?
Signup and view all the answers
Which of the following accurately describes stroke volume (SV)?
Which of the following accurately describes stroke volume (SV)?
Signup and view all the answers
What is the approximate percentage of end-diastolic volume (EDV) that stroke volume (SV) represents?
What is the approximate percentage of end-diastolic volume (EDV) that stroke volume (SV) represents?
Signup and view all the answers
Which condition is associated with a lower ejection fraction?
Which condition is associated with a lower ejection fraction?
Signup and view all the answers
What causes the small but sharp increase in left atrial pressure following AV valve closure?
What causes the small but sharp increase in left atrial pressure following AV valve closure?
Signup and view all the answers
When does the aortic valve begin to open during the cardiac cycle?
When does the aortic valve begin to open during the cardiac cycle?
Signup and view all the answers
What happens to the pressure in the left ventricle during isovolumetric relaxation?
What happens to the pressure in the left ventricle during isovolumetric relaxation?
Signup and view all the answers
What occurs during isovolumetric relaxation of the ventricles?
What occurs during isovolumetric relaxation of the ventricles?
Signup and view all the answers
What happens when the atrial pressure becomes higher than the ventricular pressure?
What happens when the atrial pressure becomes higher than the ventricular pressure?
Signup and view all the answers
Which valve has only two cusps?
Which valve has only two cusps?
Signup and view all the answers
Which sound is produced when the semilunar valves close?
Which sound is produced when the semilunar valves close?
Signup and view all the answers
Which heart sound is heard in early diastole and is considered pathological?
Which heart sound is heard in early diastole and is considered pathological?
Signup and view all the answers
Which heart sound is heard in late diastole and is associated with ventricular hypertrophy?
Which heart sound is heard in late diastole and is associated with ventricular hypertrophy?
Signup and view all the answers
Which valve is closed during the isovolumetric contraction phase of the cardiac cycle?
Which valve is closed during the isovolumetric contraction phase of the cardiac cycle?
Signup and view all the answers
Which heart sound is associated with ventricular hypertrophy?
Which heart sound is associated with ventricular hypertrophy?
Signup and view all the answers
What happens to the pressure in the ventricles during the isovolumetric relaxation phase?
What happens to the pressure in the ventricles during the isovolumetric relaxation phase?
Signup and view all the answers
During which phase of the cardiac cycle does rapid ventricular filling occur?
During which phase of the cardiac cycle does rapid ventricular filling occur?
Signup and view all the answers
During which phase of the cardiac cycle are the mitral and tricuspid valves closed?
During which phase of the cardiac cycle are the mitral and tricuspid valves closed?
Signup and view all the answers
Study Notes
Cardiac Cycle Sequence
- The correct sequence of mechanical events in the cardiac cycle is: atrial contraction, isovolumetric contraction, ventricular ejection, isovolumetric relaxation, ventricular filling, and atrial relaxation.
Isovolumetric Contraction Phase
- During the isovolumetric contraction phase, the ventricle contracts while the volume of blood remains constant.
Atrial Contraction Phase
- The purpose of the atrial contraction phase is to pump additional blood into the ventricles.
Isovolumetric Relaxation Phase
- During the isovolumetric relaxation phase, the ventricle relaxes and the pressure in the ventricles drops, leading to the closure of the semilunar valves.
Ventricular Diastole
- The term for the minimum amount of blood in the ventricles during ventricular diastole is end-systolic volume (ESV).
Ventricular Ejection Phase
- During the ventricular ejection phase, the semilunar valves open and blood is ejected from the ventricles.
Atrial Contraction Effects
- During atrial contraction, the orifices of the SVC and IVC narrow due to the increased pressure.
- Ventricular contraction causes atrial pressure to decrease.
Ventricular Relaxation
- The closure of the semilunar valves marks the beginning of ventricular relaxation.
- At the onset of ventricular relaxation, the pressure in the ventricles drops below the pressure in the atria.
- The purpose of the dichroitic notch in ventricular relaxation is to slow down the rapid drop in ventricular pressure.
Atrial Relaxation
- The purpose of atrial relaxation during ventricular diastole is to allow the ventricles to fill with blood.
Atrial Systole
- During atrial systole, an additional 10-15% of blood enters the ventricles.
- The orifices in the atrium narrow during atrial systole.
- Venous return increases during atrial systole.
Ventricular Systole
- During ventricular systole, the ventricular muscle contracts, causing the AV valves to close.
- The sound produced by this closure is called the first heart sound (S1).
Ejection Phase
- During the ejection phase, the pressure in the ventricles increases.
Ventricular Diastole
- During ventricular diastole, the pressure in the ventricles drops below the pressure in the atria.
- The AV valves open when the pressure in the ventricles drops below the pressure in the atria.
Ventricular Diastole Initiation
- The main factor that initiates ventricular diastole is the closure of the semilunar valves.
Isovolumetric Relaxation Phase
- During the isovolumetric relaxation phase, the pressure in the ventricles drops rapidly.
Stroke Volume
- Stroke volume (SV) is the amount of blood ejected from the ventricles during ventricular contraction.
- Stroke volume (SV) represents approximately 60-70% of end-diastolic volume (EDV).
Ejection Fraction
- An ejection fraction of less than 60% is associated with heart failure.
Left Atrial Pressure
- The small but sharp increase in left atrial pressure following AV valve closure is caused by the contraction of the atrium.
Aortic Valve
- The aortic valve begins to open during the ventricular ejection phase.
Isovolumetric Relaxation
- During the isovolumetric relaxation phase, the pressure in the left ventricle drops rapidly.
Ventricular Relaxation
- During isovolumetric relaxation, the ventricles relax and the pressure in the ventricles drops.
AV Valve
- When the atrial pressure becomes higher than the ventricular pressure, the AV valves open.
Pulmonary Valve
- The pulmonary valve has only two cusps.
Heart Sounds
- The sound produced when the semilunar valves close is called the second heart sound (S2).
- The third heart sound (S3) is heard in early diastole and is considered pathological.
- The fourth heart sound (S4) is heard in late diastole and is associated with ventricular hypertrophy.
Isovolumetric Contraction Phase
- The AV valves are closed during the isovolumetric contraction phase of the cardiac cycle.
Ventricular Hypertrophy
- The fourth heart sound (S4) is associated with ventricular hypertrophy.
Ventricular Filling
- Rapid ventricular filling occurs during the ventricular filling phase.
Mitral and Tricuspid Valves
- The mitral and tricuspid valves are closed during the isovolumetric contraction phase of the cardiac cycle.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge of the cardiac cycle and its duration with this quiz. Learn about systole, diastole, and the sequence of changes in pressure and blood flow in the heart chambers and blood vessels. Explore how heart rate affects the duration of diastole and more.
