Cardiovascular System

Topics in this chapter

• Cardiac Electrical Activity and ECG
• Cardiac Cycle and Pump Function
• Hemodynamics and Vascular Resistance
• Blood Pressure and Autonomic Regulation
• Regional Blood Flow and Autoregulation

Practice questions

1. Question 1Q-199FAB

   A 55-year-old male with long-standing hypertension undergoes an echocardiogram, which reveals left ventricular hypertrophy and impaired early diastolic filling. During which phase of the cardiac cycle does the majority of normal ventricular filling occur?

   1. A.Atrial systole
   2. B.Rapid ventricular filling phase
   3. C.Reduced ventricular filling phase (diastasis)
   4. D.Isovolumetric relaxation
   See the answer and solution
2. Question 2Q-B446D2

   During an experiment on isolated cardiac muscle, a researcher records an action potential with a prominent and prolonged plateau phase. Which ionic current is primarily responsible for maintaining this plateau phase (Phase 2) in ventricular myocardial cells?

   1. A.Inward fast sodium current
   2. B.Inward L-type calcium current
   3. C.Outward transient outward potassium current
   4. D.Outward inwardly rectifying potassium current
   See the answer and solution
3. Question 3Q-2E867A

   A 65-year-old patient is diagnosed with severe aortic stenosis. Which of the following pressure-volume loop alterations is expected in this patient?

   1. A.Shift of the entire loop to the left with decreased end-systolic volume
   2. B.Increased end-diastolic volume with a shifted end-diastolic pressure-volume relationship curve
   3. C.Increased peak systolic left ventricular pressure with a markedly narrowed pulse pressure
   4. D.Increased stroke volume due to prolonged ejection time
   See the answer and solution
4. Question 4Q-1A1B3D

   Which of the following interventions or conditions typically results in an increased ejection fraction (EF)?

   1. A.Administration of a negative inotropic drug
   2. B.Increased systemic arterial pressure (increased afterload)
   3. C.Sympathetic stimulation via beta-1 receptor activation
   4. D.Dilated cardiomyopathy with impaired contractility
   See the answer and solution
5. Question 5Q-F045E9

   On an electrocardiogram (ECG), the PR interval represents which of the following electrophysiological events?

   1. A.Time taken for atrial depolarization only
   2. B.Time from the onset of atrial depolarization to the onset of ventricular depolarization
   3. C.Total duration of ventricular depolarization and repolarization
   4. D.Delay of impulse conduction through the bundle of His alone
   See the answer and solution