NEET UG - Body fluids and circulation - heart structure cardiac cycle ECG blood vessels lymph Online Test (MCQ Quiz)

1. What is the primary function of the heart in the circulatory system?

A) To filter waste products from the blood B) To transport oxygen and nutrients to tissues C) To pump blood throughout the body D) To regulate blood pressure

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. The valve between the right atrium and the right ventricle is called the:

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

4. Oxygenated blood returns from the lungs to the heart via the:

A) Pulmonary artery B) Aorta C) Pulmonary veins D) Vena cava

5. Which part of the heart wall is the thickest and most muscular?

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

6. The sinoatrial (SA) node is often called the:

A) Pacemaker of the heart B) Atrioventricular (AV) node C) Bundle of His D) Purkinje fibers

7. What is the sequence of electrical conduction through the heart?

A) SA node -> AV node -> Bundle of His -> Purkinje fibers B) AV node -> SA node -> Purkinje fibers -> Bundle of His C) SA node -> Bundle of His -> AV node -> Purkinje fibers D) AV node -> Purkinje fibers -> SA node -> Bundle of His

8. The P wave on an electrocardiogram (ECG) represents:

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

9. The QRS complex on an ECG primarily indicates:

A) Atrial contraction B) Ventricular contraction C) Atrial relaxation D) Ventricular relaxation

10. What does the T wave on an ECG signify?

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

11. The period of relaxation of the heart chambers is known as:

A) Systole B) Diastole C) Ejection D) Contraction

12. During ventricular systole, which valves are closed?

A) Tricuspid and Mitral valves B) Aortic and Pulmonary valves C) Tricuspid and Pulmonary valves D) Mitral and Aortic valves

13. The first heart sound ('lub') is produced by the closure of:

A) Aortic and Pulmonary valves B) Mitral and Tricuspid valves C) Aortic and Mitral valves D) Pulmonary and Tricuspid valves

14. The second heart sound ('dub') is caused by the closure of:

A) Mitral and Tricuspid valves B) Aortic and Pulmonary valves C) Aortic and Tricuspid valves D) Mitral and Pulmonary valves

15. Which blood vessel carries blood away from the heart?

A) Vein B) Capillary C) Artery D) Venule

16. Which blood vessel carries blood towards the heart?

A) Artery B) Arteriole C) Vein D) Capillary

17. The smallest blood vessels where exchange of gases, nutrients, and waste occurs are called:

A) Arterioles B) Venules C) Capillaries D) Veins

18. Which artery carries deoxygenated blood from the right ventricle to the lungs?

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

19. The largest artery in the human body is the:

A) Pulmonary artery B) Femoral artery C) Aorta D) Brachial artery

20. Which vein collects deoxygenated blood from the lower body and empties it into the right atrium?

A) Pulmonary vein B) Superior vena cava C) Inferior vena cava D) Hepatic vein

21. The walls of arteries are generally thicker and more muscular than veins because they:

A) Need to carry deoxygenated blood B) Need to withstand higher blood pressure C) Need to prevent backflow of blood D) Need to facilitate gas exchange

22. Veins have valves to:

A) Increase blood flow velocity B) Prevent backflow of blood C) Regulate blood pressure D) Oxygenate the blood

23. The lymphatic system is responsible for:

A) Transporting oxygen to tissues B) Removing waste products from blood C) Returning excess interstitial fluid to the bloodstream D) Pumping blood throughout the body

24. Lymph is derived from:

A) Blood plasma B) Interstitial fluid C) Cerebrospinal fluid D) Synovial fluid

25. Lymphatic vessels collect excess fluid from:

A) Inside blood vessels B) The spaces between cells (interstitial spaces) C) The lumen of arteries D) The chambers of the heart

26. Which of the following is NOT a component of the lymphatic system?

A) Lymph nodes B) Lymphatic vessels C) Lymph D) Red blood cells

27. Lymph nodes are important for:

A) Producing red blood cells B) Filtering lymph and housing immune cells C) Transporting oxygen D) Pumping lymph

28. The primary artery originating from the left ventricle is the:

A) Pulmonary artery B) Aorta C) Superior vena cava D) Inferior vena cava

29. The valve that prevents the backflow of blood from the left ventricle to the left atrium is the:

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

30. The sinoatrial (SA) node is located in the wall of the:

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

31. The atrioventricular (AV) node is located at the junction of the:

A) Atria and ventricles B) Ventricles and aorta C) Atria and pulmonary artery D) Ventricles and vena cava

32. During atrial systole, the:

A) Ventricles contract B) Atria contract, pushing blood into the ventricles C) Ventricles relax D) Atria relax

33. The Q wave in an ECG represents:

A) Repolarization of the atria B) Depolarization of the ventricles C) Repolarization of the ventricles D) Depolarization of the atria

34. The ST segment on an ECG represents:

A) The period between ventricular depolarization and repolarization B) Atrial repolarization C) Ventricular repolarization D) Atrial depolarization

35. The amount of blood pumped out by each ventricle in one minute is called:

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

36. The volume of blood pumped out by one ventricle during each cardiac cycle is known as:

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

37. Which of the following factors can increase heart rate?

A) Parasympathetic stimulation B) Vagal stimulation C) Sympathetic stimulation D) Increased blood volume

38. The epicardium is also known as the:

A) Inner lining of the heart chambers B) Muscular layer of the heart wall C) Outer layer of the heart wall D) Thickest layer of the heart wall

39. The endocardium is continuous with the lining of:

A) The pericardial sac B) The large blood vessels connected to the heart C) The diaphragm D) The lungs

40. The pulmonary circulation involves the flow of blood from the:

A) Left ventricle to the body and back to the right atrium B) Right ventricle to the lungs and back to the left atrium C) Left atrium to the lungs and back to the right ventricle D) Right atrium to the body and back to the left ventricle

41. The systemic circulation involves the flow of blood from the:

A) Right ventricle to the lungs and back to the left atrium B) Left ventricle to the body and back to the right atrium C) Left atrium to the body and back to the right ventricle D) Right atrium to the lungs and back to the left ventricle

42. Which of the following is a characteristic of capillaries?

A) Thick, muscular walls B) Valves present C) Permeable walls for exchange D) Carry blood away from the heart

43. The main function of lymph is to:

A) Carry oxygen to cells B) Transport nutrients absorbed from the digestive system C) Drain excess interstitial fluid and return it to the blood D) Clot blood

44. The lymphatic system plays a crucial role in:

A) Gas exchange in the lungs B) Digestion of fats C) Immunity and fluid balance D) Hormone transport

45. The Bundle of His is part of the:

A) Valvular system of the heart B) Electrical conduction system of the heart C) Muscular wall of the ventricles D) Outer protective layer of the heart

46. Purkinje fibers are specialized cells that:

A) Initiate the heartbeat B) Conduct electrical impulses rapidly throughout the ventricular myocardium C) Regulate blood pressure in arteries D) Filter waste from blood in the kidneys

47. The closure of the aortic valve occurs at the beginning of:

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

48. The closure of the mitral valve occurs at the beginning of:

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

49. The average heart rate for a resting adult is typically:

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

50. Which of the following is NOT a function of blood?

A) Transport of oxygen and carbon dioxide B) Regulation of body temperature C) Production of antibodies D) Mechanical support for organs

Body fluids and circulation - heart structure cardiac cycle ECG blood vessels lymph - Online Test

Test Results