L19 Cardiac Output

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What is the definition of cardiac output?

Volume of blood in each ventricle at the end of systole

Volume of blood pumped by the heart per second

Volume of blood pumped by each ventricle per minute (correct)

Volume of blood returning to the right side of the heart per minute

If the stroke volume is 70 ml and the heart rate is 70 beats per minute, what is the cardiac output?

4900 ml/min (correct)

4950 ml/min

5000 ml/min

4850 ml/min

What is the normal range for ejection fraction?

Greater than 70%

Greater than 80%

Greater than 60% (correct)

Greater than 50%

Which of the following statements is true about cardiac index?

It is the volume of blood pumped by each ventricle per meter square body surface area per minute Signup and view all the answers

What is the normal value for cardiac index?

3.2 L/m^2/min Signup and view all the answers

Which of the following statements is true about venous return?

It is the volume of blood returning to the right side of the heart per minute Signup and view all the answers

What is the relationship between venous return and cardiac output?

Venous return is equal to cardiac output Signup and view all the answers

How is ejection fraction commonly measured?

Echocardiography Signup and view all the answers

What is the primary purpose of echocardiography in relation to cardiac output?

To estimate end-diastolic and end-systolic volumes, and stroke volume Signup and view all the answers

Which of the following conditions is NOT associated with a pathological increase in cardiac output?

Mitral stenosis Signup and view all the answers

Which principle is used to measure cardiac output by the dye dilution method?

Indicator dilution Signup and view all the answers

Which of the following is a physiological factor that decreases cardiac output?

Standing position Signup and view all the answers

What is the term used to describe the end-diastolic volume, which determines the initial length of the muscle fibers and the degree of stretch of the myocardium?

Preload Signup and view all the answers

Which method is used to measure cardiac output based on the principle of oxygen consumption?

Fick's principle Signup and view all the answers

Which of the following conditions is associated with a pathological decrease in cardiac output?

Anemia Signup and view all the answers

What is the term used to describe the resistance against which the heart must pump blood, primarily determined by arterial blood pressure?

Afterload Signup and view all the answers

What happens to stroke volume when venous return increases?

Increases Signup and view all the answers

Which factor does NOT affect venous return?

Blood viscosity Signup and view all the answers

What does afterload refer to in the context of the cardiovascular system?

Resistance during ventricular relaxation Signup and view all the answers

During a sudden rise in arterial blood pressure, what happens to stroke volume?

Decreases Signup and view all the answers

In what condition does an increase in heart rate NOT lead to an increase in cardiac output?

< 50 beats per minute Signup and view all the answers

What happens to stroke volume when heart rate increases with constant venous return?

Stays constant Signup and view all the answers

During paroxysmal tachycardia (> 200 beats per minute), what happens to the diastole?

Shortens Signup and view all the answers

What is the effect of a sudden rise in arterial blood pressure on stroke volume during the second systole?