Properties of Cardiac Muscle MCQ Quiz | Cardiovascular System

Welcome to the specialized MCQ quiz on the Properties of Cardiac Muscle. This assessment is tailored for MBBS students to test and reinforce their understanding of the fundamental physiological principles governing myocardial function. The quiz covers essential topics including the syncytial nature, action potentials, refractory periods, excitation-contraction coupling, and the unique metabolic characteristics of the heart muscle. Each question is designed to challenge your knowledge and prepare you for your examinations. After completing the quiz, you can submit your answers to see your score and review the correct responses. For your convenience, an option to download all questions with their correct answers in PDF format is also available for offline study and revision. Good luck!

1. The “functional syncytium” property of cardiac muscle is primarily due to the presence of:

2. The plateau phase (Phase 2) of the ventricular cardiac action potential is mainly caused by the influx of which ion?

3. The long absolute refractory period in cardiac muscle is crucial because it:

4. According to the Frank-Starling law of the heart, an increase in end-diastolic volume results in:

5. The “All-or-None” law as applied to the heart means that:

6. The primary mechanism of excitation-contraction coupling in cardiac muscle is:

7. Under resting conditions, the primary energy substrate for the cardiac muscle is:

8. The rapid depolarization (Phase 0) of the ventricular action potential is due to the opening of:

9. The property of cardiac muscle to generate its own electrical impulse is known as:

10. The slow diastolic depolarization (pacemaker potential) in the SA node is primarily caused by:

11. Desmosomes within the intercalated discs serve to:

12. What is the Staircase Phenomenon (Treppe) in cardiac muscle?

13. The repolarization phase (Phase 3) of the ventricular action potential is primarily caused by:

14. Compared to skeletal muscle, the T-tubules in cardiac muscle are:

15. A drug that has a positive inotropic effect on the heart would:

16. The calcium required for cardiac muscle contraction comes from:

17. What is the role of Ryanodine receptors (RyR2) in cardiac myocytes?

18. The term ‘chronotropism’ refers to an agent’s effect on:

19. The resting membrane potential of a ventricular myocyte is approximately:

20. The initial, brief repolarization (Phase 1) of the ventricular action potential is caused by:

21. In contrast to skeletal muscle, cardiac muscle contraction strength can be modulated by:

22. The term ‘lusitropy’ refers to:

23. Calcium is removed from the sarcoplasm of cardiac myocytes primarily by:

24. Which feature is characteristic of cardiac muscle but NOT skeletal muscle?

25. The upstroke of the action potential in SA nodal cells is mediated by: