MCQs on Human Cardiovascular System
1. What is the primary function of the cardiovascular system?
-
- a) Transport oxygen and nutrients
- b) Produce red blood cells
- c) Protect against infection
- d) Store calcium
Answer: a) Transport oxygen and nutrients
Description: The cardiovascular system circulates blood, transporting oxygen, nutrients, hormones, and waste products to and from body tissues. It ensures proper cellular function and homeostasis.
2. Which chamber of the heart pumps oxygenated blood into the systemic circulation?
-
- a) Right atrium
- b) Right ventricle
- c) Left atrium
- d) Left ventricle
Answer: d) Left ventricle
Description: The left ventricle pumps oxygen-rich blood into the systemic circulation via the aorta. Its thick muscular walls ensure high-pressure blood flow to the entire body.
3. What type of blood vessels carries blood away from the heart?
-
- a) Veins
- b) Arteries
- c) Capillaries
- d) Venules
Answer: b) Arteries
Description: Arteries transport blood away from the heart. Most carry oxygenated blood, except the pulmonary arteries, which carry deoxygenated blood to the lungs.
4. What is the largest artery in the human body?
-
- a) Coronary artery
- b) Aorta
- c) Pulmonary artery
- d) Carotid artery
Answer: b) Aorta
Description: The aorta is the largest artery, originating from the left ventricle. It distributes oxygenated blood to the systemic circulation through its various branches.
5. What are the smallest blood vessels in the body?
-
- a) Arterioles
- b) Venules
- c) Capillaries
- d) Sinusoids
Answer: c) Capillaries
Description: Capillaries are microscopic blood vessels where gas, nutrient, and waste exchange occur between blood and tissues. Their thin walls facilitate efficient diffusion.
6. Which valve prevents backflow of blood from the left ventricle to the left atrium?
-
- a) Tricuspid valve
- b) Pulmonary valve
- c) Aortic valve
- d) Mitral valve
Answer: d) Mitral valve
Description: The mitral valve, also called the bicuspid valve, prevents backflow of blood into the left atrium during ventricular contraction. It ensures unidirectional blood flow.
7. What is the normal pacemaker of the heart?
-
- a) AV node
- b) Purkinje fibers
- c) SA node
- d) Bundle of His
Answer: c) SA node
Description: The sinoatrial (SA) node, located in the right atrium, is the heart's natural pacemaker. It generates electrical impulses that initiate the heartbeat and regulate its rhythm.
8. Which component of blood is responsible for oxygen transport?
-
- a) White blood cells
- b) Platelets
- c) Red blood cells
- d) Plasma
Answer: c) Red blood cells
Description: Red blood cells (erythrocytes) contain hemoglobin, a protein that binds oxygen in the lungs and releases it to tissues, ensuring oxygen delivery throughout the body.
9. What causes the "lub-dub" sound of the heart?
-
- a) Heart muscle contraction
- b) Closing of heart valves
- c) Blood flow through arteries
- d) Electrical activity of the heart
Answer: b) Closing of heart valves
Description: The "lub-dub" sound is caused by the closure of heart valves. The "lub" is due to atrioventricular valves closing, and the "dub" is from the semilunar valves closing.
10. Which part of the ECG represents ventricular depolarization?
-
- a) P wave
- b) T wave
- c) QRS complex
- d) PR interval
Answer: c) QRS complex
Description: The QRS complex on an ECG represents ventricular depolarization, the electrical activity that triggers ventricular contraction. It is a crucial indicator of heart function.
11. Which blood vessel carries oxygenated blood from the lungs to the heart?
-
- a) Pulmonary artery
- b) Pulmonary vein
- c) Inferior vena cava
- d) Superior vena cava
Answer: b) Pulmonary vein
Description: The pulmonary veins carry oxygenated blood from the lungs to the left atrium of the heart, ensuring oxygen-rich blood is delivered for systemic circulation.
12. What is the primary function of the coronary arteries?
-
- a) Supply blood to the lungs
- b) Supply blood to the heart muscle
- c) Drain blood from the heart
- d) Prevent backflow of blood
Answer: b) Supply blood to the heart muscle
Description: Coronary arteries supply oxygen-rich blood to the myocardium (heart muscle). Proper coronary circulation is vital for the heart's function and health.
13. What is the name of the outermost layer of the heart?
-
- a) Myocardium
- b) Endocardium
- c) Pericardium
- d) Epicardium
Answer: c) Pericardium
Description: The pericardium is a double-layered membrane that surrounds the heart, providing protection, lubrication, and anchoring the heart within the thoracic cavity.
14. Which term refers to the contraction phase of the heart?
-
- a) Diastole
- b) Systole
- c) Repolarization
- d) Depolarization
Answer: b) Systole
Description: Systole is the phase of the cardiac cycle where the heart contracts, pumping blood into the arteries. It is essential for circulating blood through the body.
15. What is the role of hemoglobin in the cardiovascular system?
-
- a) Blood clotting
- b) Transporting oxygen and carbon dioxide
- c) Fighting infections
- d) Regulating blood pressure
Answer: b) Transporting oxygen and carbon dioxide
Description: Hemoglobin in red blood cells binds oxygen in the lungs and delivers it to tissues while carrying carbon dioxide back to the lungs for exhalation.
16. What is the main function of the atrioventricular (AV) node in the heart?
-
- a) Initiates the heartbeat
- b) Delays electrical impulses from the atria to ventricles
- c) Pumps blood to the lungs
- d) Regulates blood pressure
Answer: b) Delays electrical impulses from the atria to ventricles
Description: The AV node delays electrical impulses to allow the atria to contract fully before the ventricles begin to contract, ensuring efficient blood flow through the heart.
17. Which part of the heart has the thickest muscular wall?
-
- a) Right atrium
- b) Left atrium
- c) Right ventricle
- d) Left ventricle
Answer: d) Left ventricle
Description: The left ventricle has the thickest muscular wall because it pumps oxygenated blood to the entire body under high pressure, requiring significant force.
18. Which component of the blood is primarily responsible for clotting?
-
- a) Platelets
- b) Red blood cells
- c) Plasma
- d) White blood cells
Answer: a) Platelets
Description: Platelets, or thrombocytes, play a critical role in blood clotting by aggregating at injury sites and forming clots to prevent excessive blood loss.
19. What is the name of the circuit that carries blood from the heart to the lungs and back?
-
- a) Systemic circulation
- b) Coronary circulation
- c) Pulmonary circulation
- d) Portal circulation
Answer: c) Pulmonary circulation
Description: Pulmonary circulation carries deoxygenated blood from the right ventricle to the lungs for oxygenation and returns oxygenated blood to the left atrium of the heart.
20. What is the normal range for blood pressure in adults?
-
- a) 100/60 mmHg
- b) 120/80 mmHg
- c) 140/90 mmHg
- d) 160/100 mmHg
Answer: b) 120/80 mmHg
Description: A normal adult blood pressure reading is around 120/80 mmHg, where 120 represents systolic pressure (heart contraction) and 80 represents diastolic pressure (heart relaxation).
21. Which protein in plasma helps maintain oncotic pressure?
-
- a) Albumin
- b) Fibrinogen
- c) Globulin
- d) Hemoglobin
Answer: a) Albumin
Description: Albumin, a plasma protein, helps maintain oncotic pressure by regulating the movement of water between blood vessels and surrounding tissues.
22. What is the function of the pulmonary valve?
-
- a) Prevent backflow into the right ventricle
- b) Prevent backflow into the left ventricle
- c) Prevent backflow into the right atrium
- d) Prevent backflow into the left atrium
Answer: a) Prevent backflow into the right ventricle
Description: The pulmonary valve prevents the backflow of blood from the pulmonary artery into the right ventricle during diastole, ensuring unidirectional blood flow.
23. What is the function of baroreceptors in the cardiovascular system?
-
- a) Detect blood pH levels
- b) Detect blood pressure changes
- c) Regulate oxygen levels
- d) Stimulate red blood cell production
Answer: b) Detect blood pressure changes
Description: Baroreceptors are sensory receptors in the aorta and carotid arteries that detect blood pressure changes and help regulate cardiovascular responses to maintain homeostasis.
24. Which vein is the largest in the human body?
-
- a) Jugular vein
- b) Pulmonary vein
- c) Inferior vena cava
- d) Superior vena cava
Answer: c) Inferior vena cava
Description: The inferior vena cava is the largest vein in the body, returning deoxygenated blood from the lower body to the right atrium of the heart.
25. What is the primary function of white blood cells in the cardiovascular system?
-
- a) Transport oxygen
- b) Fight infections
- c) Maintain blood volume
- d) Carry nutrients
Answer: b) Fight infections
Description: White blood cells (leukocytes) play a key role in immunity by identifying and destroying pathogens, ensuring protection against infections and foreign invaders.
26. Which layer of blood vessels is composed primarily of smooth muscle?
-
- a) Tunica externa
- b) Tunica media
- c) Tunica intima
- d) Endothelium
Answer: b) Tunica media
Description: The tunica media is the middle layer of blood vessels, primarily composed of smooth muscle. It controls vessel diameter and blood pressure through vasoconstriction and vasodilation.
27. What is the heart rate of a healthy adult at rest?
-
- a) 40–60 beats per minute
- b) 60–100 beats per minute
- c) 100–140 beats per minute
- d) 140–180 beats per minute
Answer: b) 60–100 beats per minute
Description: A normal resting heart rate in adults ranges from 60 to 100 beats per minute. This reflects the balance between the sympathetic and parasympathetic nervous systems.
28. What is the purpose of the foramen ovale in the fetal heart?
-
- a) Connects the right atrium to the left atrium
- b) Connects the aorta to the pulmonary artery
- c) Connects the umbilical vein to the liver
- d) Closes off oxygenated blood flow
Answer: a) Connects the right atrium to the left atrium
Description: The foramen ovale is an opening in the fetal heart that allows blood to bypass the lungs by directly connecting the right atrium to the left atrium. It closes after birth.
29. Which type of blood vessel has the lowest blood pressure?
-
- a) Arteries
- b) Veins
- c) Capillaries
- d) Arterioles
Answer: b) Veins
Description: Veins carry blood back to the heart under low pressure. Valves in veins prevent backflow, and surrounding muscles aid in pushing blood toward the heart.
30. Which structure in the heart prevents the mixing of oxygenated and deoxygenated blood?
-
- a) Septum
- b) Aorta
- c) Coronary artery
- d) Chordae tendineae
Answer: a) Septum
Description: The septum is a muscular wall that divides the heart into right and left halves, preventing the mixing of oxygenated and deoxygenated blood between the atria and ventricles.
31. What is the function of the chordae tendineae in the heart?
-
- a) Conduct electrical impulses
- b) Prevent backflow of blood
- c) Anchor heart valves to the ventricular walls
- d) Facilitate blood flow
Answer: c) Anchor heart valves to the ventricular walls
Description: The chordae tendineae are fibrous cords that connect the atrioventricular valves (tricuspid and mitral) to the papillary muscles, preventing valve prolapse during ventricular contraction.
32. What happens during ventricular diastole?
-
- a) Ventricles contract
- b) Ventricles relax and fill with blood
- c) Blood is pumped into the pulmonary artery
- d) Heart valves close
Answer: b) Ventricles relax and fill with blood
Description: During ventricular diastole, the ventricles relax, and blood flows from the atria into the ventricles through the open atrioventricular valves.
33. Which structure initiates and regulates the heart’s rhythmic contractions?
-
- a) AV node
- b) SA node
- c) Purkinje fibers
- d) Bundle of His
Answer: b) SA node
Description: The sinoatrial (SA) node, located in the right atrium, acts as the natural pacemaker of the heart, generating electrical impulses that regulate the heartbeat.
34. Which vessel delivers deoxygenated blood to the liver for detoxification?
-
- a) Portal vein
- b) Hepatic vein
- c) Inferior vena cava
- d) Pulmonary vein
Answer: a) Portal vein
Description: The portal vein carries nutrient-rich but deoxygenated blood from the digestive tract to the liver, where detoxification and metabolism occur.
35. What type of blood vessels have valves to prevent backflow?
-
- a) Arteries
- b) Capillaries
- c) Veins
- d) Arterioles
Answer: c) Veins
Description: Veins have valves that prevent the backflow of blood, ensuring one-way circulation as blood returns to the heart under low pressure.
36. Which term refers to a condition where blood flow to the heart is blocked, often causing chest pain or heart attack?
-
- a) Hypertension
- b) Atherosclerosis
- c) Myocardial infarction
- d) Arrhythmia
Answer: c) Myocardial infarction
Description: A myocardial infarction, commonly called a heart attack, occurs when blood flow to the heart muscle is blocked, often due to atherosclerosis or a clot in the coronary arteries.
37. What is the main difference between pulmonary and systemic circulation?
Answer: b) Pulmonary circulation exchanges gases in the lungs; systemic supplies oxygen to tissues
Description: Pulmonary circulation exchanges gases in the lungs, oxygenating blood, while systemic circulation delivers oxygen-rich blood to tissues and returns deoxygenated blood to the heart.
38. What causes the T wave on an ECG?
-
- a) Atrial depolarization
- b) Ventricular depolarization
- c) Atrial repolarization
- d) Ventricular repolarization
Answer: d) Ventricular repolarization
Description: The T wave on an ECG represents ventricular repolarization, the recovery phase after the ventricles contract, preparing them for the next cardiac cycle.
39. Which heart valve is located between the right atrium and right ventricle?
-
- a) Tricuspid valve
- b) Mitral valve
- c) Aortic valve
- d) Pulmonary valve
Answer: a) Tricuspid valve
Description: The tricuspid valve prevents backflow of blood from the right ventricle into the right atrium during ventricular contraction, ensuring unidirectional flow.
40. What is the main component of plasma in the blood?
-
- a) Proteins
- b) Water
- c) Electrolytes
- d) Glucose
Answer: b) Water
Description: Plasma is the liquid portion of blood, consisting mostly of water (about 90%). It acts as a medium for transporting nutrients, hormones, and waste products.
41. What is the significance of the QRS complex in an ECG?
-
- a) Atrial depolarization
- b) Ventricular depolarization
- c) Atrial repolarization
- d) Ventricular repolarization
Answer: b) Ventricular depolarization
Description: The QRS complex represents ventricular depolarization, indicating the electrical activation that triggers ventricular contraction and is essential for pumping blood.
42. Which artery supplies the heart muscle with oxygen-rich blood?
-
- a) Coronary artery
- b) Pulmonary artery
- c) Carotid artery
- d) Aorta
Answer: a) Coronary artery
Description: Coronary arteries originate from the base of the aorta and supply oxygen-rich blood to the myocardium, ensuring the heart muscle functions properly.
43. What condition is characterized by the narrowing of blood vessels due to plaque buildup?
-
- a) Hypertension
- b) Atherosclerosis
- c) Myocarditis
- d) Pericarditis
Answer: b) Atherosclerosis
Description: Atherosclerosis is the buildup of fatty plaques on the inner walls of arteries, causing vessel narrowing and reduced blood flow, which may lead to heart attacks or strokes.
44. What is the primary purpose of the aortic valve?
-
- a) Prevent backflow into the right ventricle
- b) Prevent backflow into the left ventricle
- c) Regulate blood flow to the lungs
- d) Regulate blood pressure
Answer: b) Prevent backflow into the left ventricle
Description: The aortic valve prevents the backflow of blood from the aorta into the left ventricle during diastole, ensuring unidirectional blood flow to the systemic circulation.
45. What is the role of hemoglobin in red blood cells?
-
- a) Blood clotting
- b) Transport oxygen and carbon dioxide
- c) Maintain blood pressure
- d) Regulate body temperature
Answer: b) Transport oxygen and carbon dioxide
Description: Hemoglobin binds oxygen in the lungs and delivers it to tissues, while also carrying carbon dioxide from tissues back to the lungs for exhalation.
46. Which layer of the heart is responsible for its contraction?
-
- a) Endocardium
- b) Myocardium
- c) Epicardium
- d) Pericardium
Answer: b) Myocardium
Description: The myocardium is the thick, muscular middle layer of the heart. It is responsible for the contraction of the heart that pumps blood throughout the body.
47. Which of the following is the primary factor that affects blood pressure?
-
- a) Blood volume
- b) Heart rate
- c) Blood viscosity
- d) All of the above
Answer: d) All of the above
Description: Blood pressure is influenced by factors like blood volume, heart rate, and blood viscosity. Changes in any of these factors can significantly alter blood pressure levels.
48. Which part of the heart receives oxygenated blood from the lungs?
-
- a) Right atrium
- b) Left atrium
- c) Right ventricle
- d) Left ventricle
Answer: b) Left atrium
Description: The left atrium receives oxygenated blood from the lungs via the pulmonary veins, then pumps it into the left ventricle for distribution to the body.
49. Which blood vessels are responsible for the exchange of gases, nutrients, and waste products?
-
- a) Arteries
- b) Veins
- c) Capillaries
- d) Arterioles
Answer: c) Capillaries
Description: Capillaries are the smallest blood vessels where the exchange of gases, nutrients, and waste products occurs between blood and tissues due to their thin walls.
50. What is the function of the left ventricle in the heart?
-
- a) Pump blood to the lungs
- b) Pump blood to the systemic circulation
- c) Pump blood to the right atrium
- d) Pump blood to the coronary arteries
Answer: b) Pump blood to the systemic circulation
Description: The left ventricle pumps oxygenated blood into the aorta, which then distributes it to the entire body, supplying tissues with the oxygen and nutrients they need.
51. Which heart sound is produced by the closing of the atrioventricular valves?
-
- a) S1 (lub)
- b) S2 (dub)
- c) S3
- d) S4
Answer: a) S1 (lub)
Description: The S1 heart sound (lub) is caused by the closure of the atrioventricular valves (mitral and tricuspid) at the beginning of ventricular systole.
52. Which part of the heart is responsible for pumping oxygenated blood to the body?
-
- a) Right atrium
- b) Left atrium
- c) Right ventricle
- d) Left ventricle
Answer: d) Left ventricle
Description: The left ventricle is responsible for pumping oxygenated blood into the aorta and through the systemic circulation, delivering oxygen to body tissues.
53. What is the normal heart rate range for an adult at rest?
-
- a) 40–60 beats per minute
- b) 60–100 beats per minute
- c) 100–120 beats per minute
- d) 120–140 beats per minute
Answer: b) 60–100 beats per minute
Description: A normal resting heart rate for adults is typically between 60 and 100 beats per minute, although athletes may have lower resting heart rates.
54. What is the term for the process of the heart muscle cells undergoing spontaneous electrical activity?
-
- a) Repolarization
- b) Depolarization
- c) Polarization
- d) Automaticity
Answer: d) Automaticity
Description: Automaticity refers to the ability of heart muscle cells, particularly those in the SA node, to generate spontaneous electrical impulses without external stimulation.
55. Which of the following is a primary characteristic of arteries?
-
- a) Carry oxygenated blood only
- b) Have thick muscular walls
- c) Contain one-way valves
- d) Are smaller than veins
Answer: b) Have thick muscular walls
Description: Arteries have thick muscular walls that allow them to withstand high-pressure blood flow from the heart and help propel blood to various parts of the body.
56. Which of the following conditions is commonly associated with high blood pressure (hypertension)?
-
- a) Coronary artery disease
- b) Hypotension
- c) Aneurysm
- d) Anemia
Answer: a) Coronary artery disease
Description: Chronic hypertension increases the risk of coronary artery disease, as it can cause damage to the blood vessels and promote plaque buildup in the arteries.
57. What is the function of the pericardium?
-
- a) Provides electrical insulation
- b) Protects the heart and reduces friction
- c) Regulates heart rate
- d) Contracts to pump blood
Answer: b) Protects the heart and reduces friction
Description: The pericardium is a double-layered membrane that surrounds the heart, providing protection and reducing friction between the heart and surrounding structures during beating.
58. Which of the following is a feature of veins?
-
- a) Thick muscular walls
- b) Carry blood away from the heart
- c) Contain valves to prevent backflow
- d) Carry oxygenated blood only
Answer: c) Contain valves to prevent backflow
Description: Veins carry deoxygenated blood toward the heart and contain valves to prevent the backflow of blood due to low pressure.
59. Which of the following is the largest artery in the body?
-
- a) Pulmonary artery
- b) Femoral artery
- c) Carotid artery
- d) Aorta
Answer: d) Aorta
Description: The aorta is the largest artery in the body, carrying oxygen-rich blood from the left ventricle to the systemic circulation.
60. Which structure in the heart is responsible for the "lub-dub" sound?
-
- a) Valves closing
- b) Blood flowing through arteries
- c) Heart muscle contraction
- d) Blood pressure changes
Answer: a) Valves closing
Description: The "lub-dub" sounds of the heart are caused by the closure of heart valves: "lub" is the closing of the AV valves, and "dub" is the closing of the semilunar valves.
61. Which condition is characterized by the abnormal narrowing of the aorta?
-
- a) Aortic stenosis
- b) Aortic aneurysm
- c) Atherosclerosis
- d) Myocardial infarction
Answer: a) Aortic stenosis
Description: Aortic stenosis is a condition where the aortic valve becomes narrowed, restricting blood flow from the left ventricle into the aorta, leading to increased workload on the heart.
62. What is the term for the period when the heart muscle is contracting and pumping blood?
-
- a) Diastole
- b) Systole
- c) Repolarization
- d) Depolarization
Answer: b) Systole
Description: Systole refers to the phase of the cardiac cycle when the heart muscle contracts to pump blood from the ventricles into the pulmonary artery and aorta.
63. What is the primary function of the right ventricle?
-
- a) Pump oxygenated blood to the body
- b) Pump deoxygenated blood to the lungs
- c) Regulate heart rate
- d) Prevent backflow of blood into the atria
Answer: b) Pump deoxygenated blood to the lungs
Description: The right ventricle pumps deoxygenated blood into the pulmonary artery, which carries it to the lungs for oxygenation.
64. Which blood vessels are responsible for carrying oxygenated blood from the lungs to the heart?
-
- a) Pulmonary arteries
- b) Pulmonary veins
- c) Jugular veins
- d) Coronary arteries
Answer: b) Pulmonary veins
Description: Pulmonary veins carry oxygenated blood from the lungs to the left atrium of the heart, which then pumps it into the left ventricle for systemic circulation.
65. What is the main function of platelets in the cardiovascular system?
-
- a) Oxygen transport
- b) Blood clotting
- c) Immune response
- d) Hormone regulation
Answer: b) Blood clotting
Description: Platelets, also known as thrombocytes, play a crucial role in blood clotting by aggregating at injury sites and forming a clot to prevent excessive bleeding.
66. Which of the following is a direct consequence of coronary artery disease?
-
- a) Stroke
- b) Heart failure
- c) Pneumonia
- d) Hypertension
Answer: b) Heart failure
Description: Coronary artery disease, caused by the buildup of plaques in coronary arteries, can reduce blood flow to the heart muscle, leading to heart failure if untreated.
67. Which valve is located between the left atrium and left ventricle?
-
- a) Tricuspid valve
- b) Pulmonary valve
- c) Mitral valve
- d) Aortic valve
Answer: c) Mitral valve
Description: The mitral valve (also called the bicuspid valve) is located between the left atrium and left ventricle. It prevents backflow of blood into the atrium during ventricular contraction.
68. Which structure in the heart serves as the natural pacemaker?
-
- a) AV node
- b) SA node
- c) Bundle of His
- d) Purkinje fibers
Answer: b) SA node
Description: The sinoatrial (SA) node, located in the right atrium, initiates electrical impulses that regulate the heart's rhythm, making it the heart's natural pacemaker.
69. Which of the following is a risk factor for developing atherosclerosis?
-
- a) High cholesterol levels
- b) Low blood pressure
- c) High levels of HDL cholesterol
- d) Physical activity
Answer: a) High cholesterol levels
Description: High levels of LDL cholesterol can contribute to the buildup of plaques in the arteries, leading to atherosclerosis, which can cause heart disease and stroke.
70. Which layer of the blood vessel is responsible for vasoconstriction and vasodilation?
-
- a) Tunica intima
- b) Tunica media
- c) Tunica externa
- d) Endothelium
Answer: b) Tunica media
Description: The tunica media, composed of smooth muscle, is responsible for the constriction and dilation of blood vessels, which helps regulate blood flow and blood pressure.
71. Which condition occurs when the heart cannot pump blood effectively to meet the body's needs?
-
- a) Hypertension
- b) Heart failure
- c) Arrhythmia
- d) Angina pectoris
Answer: b) Heart failure
Description: Heart failure occurs when the heart becomes unable to pump sufficient blood to meet the body's demands, leading to symptoms like shortness of breath, fatigue, and fluid retention.
72. What type of blood is typically found in the pulmonary arteries?
-
- a) Oxygenated blood
- b) Deoxygenated blood
- c) Mixed blood
- d) Oxygenated and deoxygenated blood
Answer: b) Deoxygenated blood
Description: The pulmonary arteries carry deoxygenated blood from the right ventricle to the lungs for oxygenation, where it will be exchanged with oxygen.
73. What is the primary function of the systemic circulation?
Answer: b) Supply oxygenated blood to body tissues
Description: Systemic circulation transports oxygenated blood from the left ventricle to the body's tissues, ensuring cells receive oxygen and nutrients for metabolism.
74. Which heart valve prevents the backflow of blood into the left ventricle after it leaves the aorta?
-
- a) Mitral valve
- b) Tricuspid valve
- c) Pulmonary valve
- d) Aortic valve
Answer: d) Aortic valve
Description: The aortic valve prevents the backflow of blood into the left ventricle after it has been pumped into the aorta, ensuring unidirectional blood flow.
75. Which condition involves inflammation of the inner lining of the heart, often due to infection?
-
- a) Myocarditis
- b) Endocarditis
- c) Pericarditis
- d) Coronary artery disease
Answer: b) Endocarditis
Description: Endocarditis is an infection or inflammation of the inner lining of the heart chambers and valves, often caused by bacterial infections, leading to serious heart complications if untreated.
76. Which of the following is the first chamber of the heart to receive oxygenated blood?
-
- a) Right atrium
- b) Left atrium
- c) Right ventricle
- d) Left ventricle
Answer: b) Left atrium
Description: The left atrium receives oxygenated blood from the pulmonary veins, which it then pumps into the left ventricle to be sent through the aorta to the body.
77. What is the primary cause of high blood pressure (hypertension)?
-
- a) Obesity
- b) Physical activity
- c) Reduced sodium intake
- d) High alcohol consumption
Answer: a) Obesity
Description: Obesity is a significant risk factor for hypertension, as excess fat tissue increases the workload on the heart and can lead to increased blood pressure.
78. What type of blood vessels are responsible for carrying blood away from the heart?
-
- a) Veins
- b) Arteries
- c) Capillaries
- d) Venules
Answer: b) Arteries
Description: Arteries carry blood away from the heart. They transport oxygenated blood (except the pulmonary arteries, which carry deoxygenated blood) to the body’s tissues.
79. Which of the following is a sign of a myocardial infarction (heart attack)?
-
- a) Severe chest pain
- b) Difficulty breathing
- c) Nausea and sweating
- d) All of the above
Answer: d) All of the above
Description: Symptoms of a myocardial infarction include severe chest pain, difficulty breathing, nausea, and sweating, often associated with a blockage in a coronary artery.
80. Which blood vessel transports deoxygenated blood to the lungs for oxygenation?
-
- a) Pulmonary veins
- b) Pulmonary arteries
- c) Aorta
- d) Coronary arteries
Answer: b) Pulmonary arteries
Description: The pulmonary arteries carry deoxygenated blood from the right ventricle to the lungs, where it is oxygenated before returning to the heart.
81. What is the term for the contraction phase of the heart cycle?
-
- a) Diastole
- b) Systole
- c) Repolarization
- d) Depolarization
Answer: b) Systole
Description: Systole refers to the contraction phase of the heart cycle, during which the ventricles contract to pump blood into the pulmonary artery and aorta.
82. Which of the following is the main component of blood responsible for clotting?
-
- a) Red blood cells
- b) Plasma
- c) Platelets
- d) White blood cells
Answer: c) Platelets
Description: Platelets are small cell fragments that play a key role in the clotting process by aggregating at sites of blood vessel injury, forming clots to prevent excessive bleeding.
83. What is the name of the artery that supplies oxygenated blood to the heart muscle?
-
- a) Pulmonary artery
- b) Coronary artery
- c) Carotid artery
- d) Renal artery
Answer: b) Coronary artery
Description: The coronary arteries supply oxygen-rich blood to the heart muscle itself. Blockages in these arteries can lead to heart attacks.
84. Which of the following is a common symptom of congestive heart failure?
-
- a) Sudden weight loss
- b) Shortness of breath
- c) Excessive thirst
- d) Increased appetite
Answer: b) Shortness of breath
Description: Shortness of breath is a common symptom of congestive heart failure, which occurs when the heart is unable to pump blood efficiently, leading to fluid buildup in the lungs.
85. Which type of blood vessels are characterized by their thin walls and ability to exchange gases and nutrients?
-
- a) Arteries
- b) Veins
- c) Capillaries
- d) Arterioles
Answer: c) Capillaries
Description: Capillaries are the smallest blood vessels with thin walls, allowing the exchange of gases, nutrients, and waste products between the blood and surrounding tissues.
86. Which chamber of the heart receives deoxygenated blood from the body?
-
- a) Right atrium
- b) Left atrium
- c) Right ventricle
- d) Left ventricle
Answer: a) Right atrium
Description: The right atrium receives deoxygenated blood from the body through the superior and inferior vena cava, and pumps it into the right ventricle for lung circulation.
87. What is the role of the SA node in the heart?
-
- a) Controls heart rate
- b) Generates electrical impulses
- c) Prevents backflow of blood
- d) Contracts the heart muscle
Answer: b) Generates electrical impulses
Description: The SA node (sinoatrial node) is the heart's natural pacemaker, responsible for generating electrical impulses that initiate each heartbeat, thus controlling the heart's rhythm.
88. What is the term for the backward flow of blood through a valve?
-
- a) Regurgitation
- b) Hypertension
- c) Aneurysm
- d) Thrombosis
Answer: a) Regurgitation
Description: Regurgitation refers to the backward flow of blood through a heart valve due to improper valve closure, which can cause symptoms such as fatigue and shortness of breath.
89. What is the name of the condition where there is a sudden loss of blood supply to the heart muscle?
-
- a) Stroke
- b) Myocardial infarction
- c) Arrhythmia
- d) Angina
Answer: b) Myocardial infarction
Description: A myocardial infarction, or heart attack, occurs when the blood supply to part of the heart muscle is blocked, causing tissue damage due to lack of oxygen.
90. Which of the following blood components helps in transporting oxygen throughout the body?
-
- a) Platelets
- b) White blood cells
- c) Red blood cells
- d) Plasma
Answer: c) Red blood cells
Description: Red blood cells contain hemoglobin, which binds to oxygen in the lungs and carries it through the bloodstream to tissues and organs.
91. Which type of artery is responsible for carrying oxygenated blood from the heart to the rest of the body?
-
- a) Pulmonary artery
- b) Carotid artery
- c) Aorta
- d) Renal artery
Answer: c) Aorta
Description: The aorta is the largest artery in the body, carrying oxygenated blood from the left ventricle to the systemic circulation for distribution to tissues and organs.
92. What is the term for the narrowing and hardening of the arteries due to plaque buildup?
-
- a) Aneurysm
- b) Atherosclerosis
- c) Angina
- d) Myocardial infarction
Answer: b) Atherosclerosis
Description: Atherosclerosis occurs when plaques made of fat, cholesterol, and other substances build up in the arterial walls, narrowing and hardening them, which can lead to heart disease.
93. Which heart chamber receives blood from the lungs?
-
- a) Left ventricle
- b) Left atrium
- c) Right atrium
- d) Right ventricle
Answer: b) Left atrium
Description: The left atrium receives oxygenated blood from the lungs via the pulmonary veins. It then pumps the blood into the left ventricle for systemic circulation.
94. What does the "lub-dub" sound of the heart represent?
-
- a) Heart contraction and relaxation
- b) Closure of heart valves
- c) Blood flow through the ventricles
- d) Electrical impulses in the heart
Answer: b) Closure of heart valves
Description: The "lub" sound is caused by the closing of the atrioventricular (AV) valves, while the "dub" sound is caused by the closing of the semilunar valves during the cardiac cycle.
95. Which type of heart disease is caused by reduced blood flow to the heart muscle?
-
- a) Rheumatic heart disease
- b) Coronary artery disease
- c) Congestive heart failure
- d) Endocarditis
Answer: b) Coronary artery disease
Description: Coronary artery disease occurs when the coronary arteries become narrowed or blocked due to plaque buildup, reducing blood flow to the heart muscle, leading to chest pain or heart attacks.
96. What is the primary function of the coronary circulation?
-
- a) To supply oxygenated blood to the lungs
- b) To supply oxygenated blood to the heart muscle
- c) To transport waste products away from the heart
- d) To distribute blood to the brain
Answer: b) To supply oxygenated blood to the heart muscle
Description: The coronary circulation consists of blood vessels that supply oxygenated blood to the heart muscle itself, ensuring it receives the nutrients necessary to function properly.
97. Which of the following can increase the risk of developing heart disease?
-
- a) High blood pressure
- b) Low cholesterol levels
- c) Regular exercise
- d) Healthy diet
Answer: a) High blood pressure
Description: High blood pressure, or hypertension, increases the risk of heart disease by damaging blood vessels, making them more susceptible to plaque buildup and narrowing.
98. Which heart valve prevents the backflow of blood into the right ventricle?
-
- a) Aortic valve
- b) Pulmonary valve
- c) Mitral valve
- d) Tricuspid valve
Answer: b) Pulmonary valve
Description: The pulmonary valve is located between the right ventricle and pulmonary artery, preventing the backflow of blood into the right ventricle after it is pumped to the lungs.
99. Which of the following is a common cause of heart murmurs?
-
- a) Valve defects
- b) Increased heart rate
- c) Poor diet
- d) High blood pressure
Answer: a) Valve defects
Description: Heart murmurs are often caused by valve defects, such as leaky or narrowed valves, which affect blood flow and cause abnormal heart sounds.
100. Which of the following is the correct sequence for the pathway of blood through the heart?
- a) Right atrium → Right ventricle → Left atrium → Left ventricle
- b) Right atrium → Left atrium → Right ventricle → Left ventricle
- c) Left atrium → Left ventricle → Right atrium → Right ventricle
- d) Left ventricle → Left atrium → Right ventricle → Right atrium
Answer: a) Right atrium → Right ventricle → Left atrium → Left ventricle
Description: Blood flows from the right atrium to the right ventricle, where it is pumped to the lungs for oxygenation. The oxygenated blood then returns to the left atrium and is pumped into the left ventricle for systemic circulation.