TRB PG Assistant - Cardiovascular system – heart structure, cardiac cycle, ECG Online Test (MCQ Quiz)

1. What is the primary function of the cardiovascular system?

A) Digestion of food B) Transport of oxygen, nutrients, and waste products C) Regulation of body temperature D) Production of hormones

2. Which chamber of the heart receives deoxygenated blood from the body?

A) Left atrium B) Right atrium C) Left ventricle D) Right ventricle

3. Oxygenated blood returns from the lungs to which chamber of the heart?

A) Right atrium B) Right ventricle C) Left atrium D) Left ventricle

4. Which valve prevents the backflow of blood from the right ventricle to the right atrium?

A) Mitral valve B) Aortic valve C) Pulmonary valve D) Tricuspid valve

5. The valve between the left atrium and the left ventricle is called the:

A) Pulmonary valve B) Tricuspid valve C) Mitral valve D) Aortic valve

6. Which valve controls the flow of blood from the left ventricle into the aorta?

A) Mitral valve B) Tricuspid valve C) Pulmonary valve D) Aortic valve

7. The muscular wall of the heart is called the:

A) Endocardium B) Pericardium C) Myocardium D) Epicardium

8. The inner lining of the heart chambers and valves is made up of:

A) Myocardium B) Epicardium C) Endocardium D) Pericardium

9. The sac that surrounds and protects the heart is known as the:

A) Endocardium B) Myocardium C) Epicardium D) Pericardium

10. The cardiac cycle begins with:

A) Ventricular systole B) Atrial diastole C) Ventricular diastole D) Atrial systole

11. What is the contraction phase of the cardiac cycle called?

A) Diastole B) Systole C) Lub D) Dub

12. What is the relaxation phase of the cardiac cycle called?

A) Systole B) Diastole C) Lub D) Dub

13. During ventricular systole, which valves close?

A) Aortic and pulmonary valves B) Mitral and tricuspid valves C) Aortic and mitral valves D) Pulmonary and tricuspid valves

14. During ventricular diastole, which valves open?

A) Aortic and pulmonary valves B) Mitral and tricuspid valves C) Aortic and mitral valves D) Pulmonary and tricuspid valves

15. The first heart sound ('lub') is produced by the closure of which valves?

A) Aortic and pulmonary valves B) Mitral and tricuspid valves C) Aortic and mitral valves D) Pulmonary and tricuspid valves

16. The second heart sound ('dub') is produced by the closure of which valves?

A) Aortic and pulmonary valves B) Mitral and tricuspid valves C) Aortic and mitral valves D) Pulmonary and tricuspid valves

17. What is the average duration of the cardiac cycle in a resting adult?

A) 0.5 seconds B) 0.8 seconds C) 1.0 seconds D) 1.5 seconds

18. What electrical event in the heart precedes atrial contraction?

A) P wave B) QRS complex C) T wave D) PR interval

19. The QRS complex on an ECG represents:

A) Atrial depolarization B) Ventricular depolarization C) Ventricular repolarization D) Atrial repolarization

20. What does the T wave on an ECG represent?

A) Atrial depolarization B) Ventricular depolarization C) Ventricular repolarization D) Atrial repolarization

21. An ECG measures the:

A) Mechanical activity of the heart B) Electrical activity of the heart C) Blood pressure in the arteries D) Oxygen saturation in the blood

22. Which part of the cardiac conduction system initiates the electrical impulse that triggers a heartbeat?

A) Atrioventricular (AV) node B) Sinoatrial (SA) node C) Bundle of His D) Purkinje fibers

23. The SA node is located in the wall of which chamber?

A) Left atrium B) Right atrium C) Left ventricle D) Right ventricle

24. The AV node is located between which two chambers?

A) Right atrium and right ventricle B) Left atrium and left ventricle C) Right ventricle and pulmonary artery D) Left ventricle and aorta

25. What is the primary role of the AV node in the cardiac conduction system?

A) To initiate the heartbeat B) To delay the impulse before it reaches the ventricles C) To rapidly conduct impulses down the ventricles D) To spread impulses across the atria

26. The electrical impulse travels from the AV node to the ventricles via the:

A) SA node B) Bundle of His and Purkinje fibers C) Coronary arteries D) Vagus nerve

27. What are Purkinje fibers responsible for?

A) Initiating the heart beat B) Conducting electrical impulses to the ventricular myocardium C) Delaying the impulse from the atria D) Regulating heart rate through hormones

28. The sympathetic nervous system generally has what effect on heart rate?

A) Decreases heart rate B) Increases heart rate C) No effect on heart rate D) Causes irregular heartbeats

29. The parasympathetic nervous system, primarily via the vagus nerve, generally has what effect on heart rate?

A) Increases heart rate B) Decreases heart rate C) No effect on heart rate D) Causes erratic contractions

30. What is the term for the volume of blood pumped by the left ventricle per minute?

A) Stroke volume B) Ejection fraction C) Cardiac output D) Heart rate

31. Cardiac output is calculated by multiplying:

A) Stroke volume and blood pressure B) Heart rate and blood volume C) Stroke volume and heart rate D) Ejection fraction and heart rate

32. The amount of blood ejected by the left ventricle with each beat is called:

A) Cardiac output B) Ejection fraction C) Stroke volume D) End-diastolic volume

33. Which of the following factors can increase stroke volume?

A) Decreased venous return B) Increased afterload C) Increased contractility D) Decreased preload

34. What is preload in the context of the cardiac cycle?

A) The resistance the ventricle must overcome to eject blood B) The degree of stretch of the ventricular muscle before contraction C) The force generated by the heart muscle during contraction D) The rate at which the heart beats

35. What is afterload in the context of the cardiac cycle?

A) The degree of stretch of the ventricular muscle before contraction B) The volume of blood in the ventricle at the end of diastole C) The resistance the ventricle must overcome to eject blood D) The amount of blood pumped per minute

36. An elevated afterload typically leads to:

A) Increased stroke volume B) Decreased stroke volume C) Increased heart rate D) Decreased heart rate

37. The P wave on an ECG represents:

A) Ventricular depolarization B) Atrial depolarization C) Ventricular repolarization D) Atrial repolarization

38. The PR interval on an ECG represents the time from the beginning of atrial depolarization to the beginning of:

A) Atrial repolarization B) Ventricular depolarization C) Ventricular repolarization D) The start of the next P wave

39. A prolonged PR interval on an ECG may indicate:

A) Rapid ventricular conduction B) Atrial fibrillation C) AV block D) Ventricular tachycardia

40. The ST segment on an ECG represents:

A) The period between ventricular depolarization and repolarization B) The beginning of ventricular depolarization C) The completion of ventricular repolarization D) Atrial contraction

41. Elevation of the ST segment on an ECG is often indicative of:

A) Bradycardia B) Myocardial infarction (heart attack) C) Tachycardia D) Atrial flutter

42. What is the term for the relaxation of the atria during the cardiac cycle?

A) Atrial systole B) Ventricular systole C) Atrial diastole D) Ventricular diastole

43. What is the term for the contraction of the ventricles during the cardiac cycle?

A) Atrial systole B) Ventricular systole C) Atrial diastole D) Ventricular diastole

44. The pulmonary valve is located between the:

A) Right atrium and right ventricle B) Right ventricle and pulmonary artery C) Left atrium and left ventricle D) Left ventricle and aorta

45. Which artery supplies oxygenated blood to the heart muscle itself?

A) Pulmonary artery B) Aorta C) Coronary artery D) Carotid artery

46. What is the average heart rate for a healthy adult at rest?

A) 40-60 beats per minute B) 60-100 beats per minute C) 100-120 beats per minute D) 120-150 beats per minute

47. The Q wave on an ECG represents:

A) Initial depolarization of the atria B) Initial depolarization of the ventricles C) Repolarization of the ventricles D) Delay at the AV node

48. Which of the following is NOT a primary function of the myocardium?

A) To contract and pump blood B) To conduct electrical impulses C) To generate heat D) To maintain the structure of the heart wall

49. During atrial systole, which valves are open?

A) Aortic and pulmonary valves B) Mitral and tricuspid valves C) Aortic and mitral valves D) Pulmonary and tricuspid valves

50. The electrical impulse travels from the SA node to the AV node through the:

A) Bundle of His B) Purkinje fibers C) Internodal pathways D) Coronary sinus

Cardiovascular system – heart structure, cardiac cycle, ECG - Online Test

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