1. The human heart is located in ___________.
A) Abdominal cavity
B) Thoracic cavity
C) Cranial cavity
D) Pelvic cavity
Answer: B
Explanation: The heart lies in the thoracic cavity between the two lungs, in the mediastinum.
2. Human heart is enclosed by a protective covering called___________.
A) Pleura
B) Peritoneum
C) Pericardium
D) Perichondrium
Answer: C
Explanation: The pericardium is a double-layered sac that protects and anchors the heart.
3. The human heart is___________.
A) Two-chambered
B) Three-chambered
C) Four-chambered
D) Five-chambered
Answer: C
Explanation: The human heart has 2 atria and 2 ventricles.
4. The right atrium receives blood from___________.
A) Pulmonary vein
B) Superior and inferior vena cava
C) Aorta
D) Coronary artery
Answer: B
Explanation: Deoxygenated blood from the body enters the right atrium via venae cavae.
5. The left atrium receives blood from___________.
A) Pulmonary artery
B) Pulmonary veins
C) Aorta
D) Superior vena cava
Answer: B
Explanation: Left atrium receives oxygenated blood from lungs via pulmonary veins.
6. Which chamber of the heart pumps blood into the lungs?
A) Right atrium
B) Left atrium
C) Right ventricle
D) Left ventricle
Answer: C
Explanation: Right ventricle pumps deoxygenated blood into pulmonary artery → lungs.
7. The strongest chamber of the heart is___________.
A) Right atrium
B) Right ventricle
C) Left atrium
D) Left ventricle
Answer: D
Explanation: Left ventricle has thickest walls to pump blood to whole body.
8. The human heart weight in adults is about___________.
A) 150 g
B) 250–300 g
C) 500 g
D) 1000 g
Answer: B
Explanation: The average heart weight is ~280 g (females slightly less).
9. The number of valves in the human heart is___________.
A) 2
B) 3
C) 4
D) 5
Answer: C
Explanation: Two atrioventricular valves (tricuspid, bicuspid) and two semilunar valves.
10. The tricuspid valve lies between___________.
A) Left atrium and left ventricle
B) Right atrium and right ventricle
C) Left ventricle and aorta
D) Right ventricle and pulmonary artery
Answer: B
Explanation: Tricuspid valve prevents backflow of blood.
11. The bicuspid (mitral) valve lies between___________.
A) Right atrium and ventricle
B) Left atrium and left ventricle
C) Right ventricle and pulmonary artery
D) Left ventricle and aorta
Answer: B
Explanation: Mitral valve allows unidirectional blood flow.
12. The pulmonary valve guards the opening of___________.
A) Aorta
B) Pulmonary artery
C) Vena cava
D) Coronary vein
Answer: B
Explanation: Pulmonary semilunar valve prevents backflow into right ventricle.
13. The aortic valve guards the opening of___________.
A) Pulmonary artery
B) Aorta
C) Vena cava
D) Coronary sinus
Answer: B
Explanation: Aortic valve prevents backflow into left ventricle.
14. Which type of blood is found in the right side of the heart?
A) Oxygenated
B) Deoxygenated
C) Both
D) None
Answer: B
Explanation: Right atrium & ventricle carry deoxygenated blood to lungs.
15. Which type of blood is found in the left side of the heart?
A) Oxygenated
B) Deoxygenated
C) Mixed
D) None
Answer: A
Explanation: Left atrium & ventricle carry oxygen-rich blood from lungs to body.
16. The natural pacemaker of the heart is___________.
A) AV node
B) SA node
C) Purkinje fibers
D) Bundle of His
Answer: B
Explanation: Sinoatrial (SA) node initiates heartbeat (~70–75 beats/min).
17. The human heart is made of___________.
A) Smooth muscle
B) Skeletal muscle
C) Cardiac muscle
D) Voluntary muscle
Answer: C
Explanation: Involuntary, striated, branched cardiac muscle forms heart wall.
18. Wall of heart consists of three layers___________.
A) Endocardium, myocardium, pericardium
B) Epidermis, dermis, hypodermis
C) Mucosa, submucosa, serosa
D) Pleura, peritoneum, periosteum
Answer: A
Explanation: Myocardium is thickest muscular layer.
19. The coronary arteries supply___________.
A) Lungs
B) Brain
C) Kidneys
D) Heart itself
Answer: D
Explanation: Coronary arteries provide oxygenated blood to myocardium.
20. Failure of coronary circulation leads to___________.
A) Asthma
B) Heart attack
C) Paralysis
D) Stroke
Answer: B
Explanation: Blockage of coronary artery → myocardial infarction (heart attack).
21. The average size of human heart is comparable to___________.
A) A fist
B) A football
C) A tennis ball
D) A brain
Answer: A
Explanation: Human heart is roughly the size of a clenched fist..
22. The number of atria in the human heart is___________.
A) 1
B) 2
C) 3
D) 4
Answer: B
Explanation: Right atrium and left atrium.
23. The number of ventricles in the human heart is___________.
A) 1
B) 2
C) 3
D) 4
Answer: B
Explanation: Right ventricle and left ventricle.
24. Which side of the heart has thicker walls?
A) Right side
B) Left side
C) Both same
D) None
Answer: B
Explanation: Left ventricle pumps blood to whole body → thickest wall.
25. The blood vessel that carries oxygenated blood from lungs to heart is___________.
A) Pulmonary vein
B) Pulmonary artery
C) Aorta
D) Vena cava
Answer: A
Explanation: Pulmonary vein carries oxygen-rich blood to left atrium.
26. Human heart shows___________.
A) Single circulation
B) Double circulation
C) Open circulation
D) No circulation
Answer: B
Explanation: Blood passes twice through the heart in one complete circuit → pulmonary and systemic circulation.
27. Pulmonary circulation carries blood between___________.
A) Heart and body tissues
B) Heart and lungs
C) Lungs and tissues
D) Heart and brain
Answer: B
Explanation: Pulmonary circulation = right ventricle → lungs → left atrium.
28. Systemic circulation carries blood between___________.
A) Heart and lungs
B) Heart and whole body
C) Heart and kidneys only
D) Heart and brain only
Answer: B
Explanation: Systemic circulation = left ventricle → body → right atrium.
29. Which blood vessel carries deoxygenated blood from heart to lungs?
A) Pulmonary vein
B) Pulmonary artery
C) Aorta
D) Vena cava
Answer: B
Explanation: Pulmonary artery carries deoxygenated blood from right ventricle to lungs.
30. Which blood vessel carries oxygenated blood from lungs to heart?
A) Pulmonary artery
B) Pulmonary vein
C) Aorta
D) Coronary artery
Answer: B
Explanation: Pulmonary vein carries oxygenated blood to left atrium.
31. Which valve prevents backflow of blood from ventricles to atria?
A) Semilunar valves
B) Bicuspid & tricuspid valves
C) Coronary valves
D) None
Answer: B
Explanation: Atrioventricular (AV) valves prevent reverse blood flow.
32. Tricuspid valve is located___________.
A) Between right atrium & ventricle
B) Between left atrium & ventricle
C) At pulmonary artery opening
D) At aorta opening
Answer: A
Explanation: Tricuspid = 3 cusps, regulates blood from RA → RV.
33. Bicuspid (mitral) valve is located___________.
A) Between right atrium & ventricle
B) Between left atrium & ventricle
C) At pulmonary artery
D) At aorta
Answer: B
Explanation: Mitral valve = 2 cusps, regulates blood from LA → LV.
34. Pulmonary semilunar valve is present at___________.
A) Right atrium
B) Pulmonary artery opening
C) Left ventricle
D) Left atrium
Answer: B
Explanation: Prevents backflow into right ventricle.
35. Aortic semilunar valve is present at___________.
A) Aorta opening
B) Pulmonary artery
C) Left atrium
D) Right atrium
Answer: A
Explanation: Prevents backflow into left ventricle.
36. Which chamber pumps blood to the whole body?
A) Right atrium
B) Right ventricle
C) Left atrium
D) Left ventricle
Answer: D
Explanation: Left ventricle → thickest wall → pumps blood to systemic circulation.
37. Which side of the heart carries oxygenated blood?
A) Right side
B) Left side
C) Both
D) None
Answer: B
Explanation: Left atrium & ventricle → oxygenated blood.
38. Which side of the heart carries deoxygenated blood?
A) Right side
B) Left side
C) Both
D) None
Answer: A
Explanation: Right atrium & ventricle → deoxygenated blood.
39. Which vein brings deoxygenated blood from the lower body to the heart?
A) Superior vena cava
B) Inferior vena cava
C) Pulmonary vein
D) Coronary vein
Answer: B
Explanation: Inferior vena cava drains lower body into right atrium.
40. Which vein brings deoxygenated blood from the upper body to the heart?
A) Inferior vena cava
B) Superior vena cava
C) Pulmonary vein
D) Coronary sinus
Answer: B
Explanation: Superior vena cava drains head, neck, arms into right atrium.
41. Which blood vessel carries oxygenated blood from heart to body?
A) Pulmonary artery
B) Aorta
C) Pulmonary vein
D) Coronary vein
Answer: B
Explanation: Aorta carries oxygen-rich blood from LV to all body parts.
42. Coronary arteries supply___________.
A) Kidneys
B) Brain
C) Heart muscle
D) Lungs
Answer: C
Explanation: Coronary arteries nourish myocardium.
43. Double circulation in humans ensures___________.
A) Mixing of oxygenated and deoxygenated blood
B) Complete separation of blood types
C) Less oxygen supply
D) Slow circulation
Answer: B
Explanation: Four-chambered heart maintains separate oxygenated and deoxygenated blood flow.
44. Which vein carries oxygenated blood?
A) Pulmonary vein
B) Pulmonary artery
C) Vena cava
D) Coronary sinus
Answer: A
Explanation: Pulmonary vein is the only vein carrying oxygen-rich blood.
45. Which artery carries deoxygenated blood?
A) Coronary artery
B) Aorta
C) Pulmonary artery
D) Carotid artery
Answer: C
Explanation: Pulmonary artery is the only artery carrying deoxygenated blood.
46. Which valves prevent backflow into atria during ventricular contraction?
A) Semilunar valves
B) Atrioventricular valves
C) Coronary valves
D) None
Answer: B
Explanation: Tricuspid and mitral valves close during ventricular systole.
47. Which valves prevent backflow into ventricles during relaxation?
A) AV valves
B) Semilunar valves
C) Coronary valves
D) None
Answer: B
Explanation: Pulmonary and aortic valves close during diastole.
48. Which side of the heart works under higher pressure?
A) Right
B) Left
C) Both equal
D) None
Answer: B
Explanation: Left ventricle pumps blood to whole body → high pressure.
49. Which circulation brings oxygen and nutrients to heart tissue?
A) Pulmonary circulation
B) Systemic circulation
C) Coronary circulation
D) Lymphatic circulation
Answer: C
Explanation: Coronary arteries supply blood to myocardium.
50. Which is the correct sequence of blood flow in pulmonary circulation?
A) RA → RV → Pulmonary artery → Lungs → Pulmonary vein → LA
B) LA → LV → Aorta → Body → Vena cava → RA
C) LV → Aorta → Body → Vena cava → RA
D) RA → Pulmonary vein → LA
Answer: A
Explanation: This is the correct pathway of pulmonary circulation.
51. The number of heartbeats per minute in a healthy adult is___________.
A) 40–50
B) 60–72
C) 80–100
D) 120–140
Answer: B
Explanation: Normal resting heart rate is about 72 beats/minute.
52. Each heartbeat lasts about___________.
A) 0.2 sec
B) 0.4 sec
C) 0.8 sec
D) 1.2 sec
Answer: C
Explanation: One complete cardiac cycle (heartbeat) takes 0.8 seconds.
53. Cardiac cycle consists of___________.
A) Atrial systole, ventricular systole, joint diastole
B) Inspiration and expiration
C) Depolarization only
D) Systole only
Answer: A
Explanation: These three phases complete one heartbeat.
54. The “lub” sound of the heart is produced by closure of___________.
A) Semilunar valves
B) AV valves (tricuspid and bicuspid)
C) Pulmonary valve only
D) Coronary valves
Answer: B
Explanation: “Lub” = closure of atrioventricular valves at start of ventricular systole.
55. The “dub” sound of the heart is produced by closure of___________.
A) AV valves
B) Semilunar valves
C) Mitral valve only
D) Tricuspid valve only|
Answer: B
Explanation: “Dub” = closure of aortic and pulmonary valves at ventricular diastole.
56. The cardiac pacemaker in the heart is___________.
A) AV node
B) SA node
C) Purkinje fibers
D) Bundle of His
Answer: B
Explanation: SA node (sinoatrial node) initiates impulse → natural pacemaker.
57. Artificial pacemaker is implanted when___________.
A) Valves are defective
B) SA node fails
C) Blood clotting decreases
D) Heart is enlarged
Answer: B
Explanation: Artificial pacemaker generates impulses when SA node fails.
58. Which node delays the impulse to allow atrial contraction?
A) SA node
B) AV node
C) Purkinje fibers
D) Bundle of His
Answer: B
Explanation: AV node introduces a delay before ventricles contract.
59. Which fibers conduct impulses to ventricular walls?
A) Purkinje fibers
B) AV node
C) SA node
D) Coronary fibers
Answer: A
Explanation: Purkinje fibers spread impulse to ventricles → contraction.
60. ECG stands for___________.
A) Electrocardiogram
B) Electrocardiograph
C) Both a and b
D) None
Answer: C
Explanation: ECG = record (gram) and instrument (graph).
61. The “P wave” in ECG represents___________.
A) Ventricular depolarization
B) Atrial depolarization
C) Ventricular repolarization
D) Heart relaxation
Answer: B
Explanation: P wave = contraction (depolarization) of atria.
62. The “QRS complex” in ECG represents___________.
A) Ventricular depolarization
B) Atrial repolarization
C) Ventricular repolarization
D) Atrial systole
Answer: A
Explanation: QRS complex = contraction of ventricles.
63. The “T wave” in ECG represents___________.
A) Atrial systole
B) Ventricular repolarization
C) Ventricular depolarization
D) Atrial depolarization
Answer: B
Explanation: T wave = relaxation of ventricles.
64. The duration of atrial systole is about___________.
A) 0.1 sec
B) 0.3 sec
C) 0.5 sec
D) 0.7 sec
Answer: A
Explanation: Atria contract for ~0.1 sec during cardiac cycle.
65. The duration of ventricular systole is about___________.
A) 0.1 sec
B) 0.3 sec
C) 0.5 sec
D) 0.7 sec
Answer: B
Explanation: Ventricles contract for ~0.3 sec.
66. The duration of joint diastole is about___________.
A) 0.1 sec
B) 0.3 sec
C) 0.4 sec
D) 0.7 sec
Answer: C
Explanation: Atria and ventricles relax together for ~0.4 sec.
67. Average cardiac output of an adult human is___________.
A) 1 L/min
B) 2 L/min
C) 5 L/min
D) 10 L/min
Answer: C
Explanation: Cardiac output = ~70 ml × 72 beats/min ≈ 5 L/min.
68. Stroke volume is about___________.
A) 20 ml
B) 40 ml
C) 70 ml
D) 200 ml
Answer: C
Explanation: Each beat pumps ~70 ml of blood.
69. Which factor does NOT increase heart rate?
A) Exercise
B) Adrenaline
C) Vagus nerve stimulation
D) Excitement
Answer: C
Explanation: Vagus nerve slows heart rate (parasympathetic).
70. Normal blood pressure in humans is___________.
A) 80/60 mmHg
B) 100/70 mmHg
C) 120/80 mmHg
D) 140/90 mmHg
Answer: C
Explanation: Normal systolic = 120 mmHg, diastolic = 80 mmHg.
71. High blood pressure is called___________.
A) Hypotension
B) Hypertension
C) Atherosclerosis
D) Arrhythmia
Answer: B
Explanation: Hypertension = persistent BP above 140/90 mmHg.
72. Low blood pressure is called___________.
A) Hypotension
B) Hypertension
C) Bradycardia
D) Tachycardia
Answer: A
Explanation: Hypotension = BP below normal (e.g., 90/60 mmHg).
73. Bradycardia means___________.
A) Abnormally slow heartbeat
B) Abnormally fast heartbeat
C) Irregular rhythm
D) No heartbeat
Answer: A
Explanation: Bradycardia = <60 beats/min.
74. Tachycardia means___________.
A) Slow heartbeat
B) Fast heartbeat
C) Heart enlargement
D) Heart block
Answer: B
Explanation: Tachycardia = >100 beats/min.
75. Pulse rate is equal to___________.
A) Respiratory rate
B) Heartbeat rate
C) Blood pressure
D) Stroke volume
Answer: B
Explanation: Pulse rate (felt at wrist) = heart rate.
76. Heart attack is medically known as___________.
A) Cardiac arrest
B) Myocardial infarction
C) Angina pectoris
D) Arrhythmia
Answer: B
Explanation: Heart attack occurs due to blockage of coronary arteries → death of cardiac muscle.
77. Sudden stoppage of heartbeat is called___________.
A) Angina
B) Cardiac arrest
C) Stroke
D) Hypertension
Answer: B
Explanation: Cardiac arrest = sudden loss of heart function.
78. Chest pain due to inadequate blood supply to heart is called___________.
A) Angina pectoris
B) Stroke
C) Asthma
D) Epilepsy
Answer: A
Explanation: Angina = pain during exertion due to poor oxygen supply.
79. Which disease is caused by narrowing of coronary arteries?
A) Coronary artery disease (CAD)
B) Hypertension
C) Asthma
D) Stroke
Answer: A
Explanation: CAD reduces blood flow to heart → angina/heart attack.
80. Which of the following is called “silent killer”?
A) Heart attack
B) Stroke
C) Hypertension
D) Atherosclerosis
Answer: C
Explanation: Hypertension shows no symptoms but damages heart, brain, kidneys.
81. Atherosclerosis is caused by___________.
A) Accumulation of fat in arteries
B) Valve defects
C) High blood sugar
D) Infection
Answer: A
Explanation: Cholesterol deposition in arteries → narrowing & hardening.
82. Rheumatic heart disease is due to___________.
A) Bacterial infection
B) Viral infection
C) Fungal infection
D) Genetic defect
Answer: A
Explanation: Streptococcal infection can damage heart valves → rheumatic heart disease.
83. Arrhythmia means___________.
A) Abnormal heart rhythm
B) High BP
C) Heart enlargement
D) Valve defect
Answer: A
Explanation: Arrhythmia = irregular heartbeat (too fast/slow).
84. Which test is used to detect electrical activity of the heart?
A) EEG
B) ECG
C) MRI
D) CT scan
Answer: B
Explanation: Electrocardiogram records electrical activity of heart.
85. Pacemaker of the heart is located in___________.
A) Right atrium
B) Left atrium
C) Right ventricle
D) Left ventricle
Answer: A
Explanation: SA node (pacemaker) lies in right atrium.
86. Heart murmur is caused by___________.
A) Valve defects
B) Coronary blockage
C) Arrhythmia
D) Hypertension
Answer: A
Explanation: Abnormal sounds (murmurs) occur due to improper valve closure.
87. Which vitamin is essential for blood clotting, reducing bleeding risk?
A) Vitamin C
B) Vitamin D
C) Vitamin K
D) Vitamin E
Answer: C
Explanation: Vitamin K helps synthesis of prothrombin, prevents hemorrhage.
88. Which lifestyle factor increases risk of heart disease?
A) Smoking
B) High-fat diet
C) Lack of exercise
D) All of these
Answer: D
Explanation: Smoking, obesity, and sedentary lifestyle → major cardiac risk factors.
89. Aspirin helps prevent heart attack by___________.
A) Lowering blood pressure
B) Preventing blood clot formation
C) Increasing heart rate
D) Strengthening heart muscle
Answer: B
Explanation: Low-dose aspirin reduces platelet aggregation.
90. Which ion is essential for normal heart contraction?
A) Sodium
B) Potassium
C) Calcium
D) Magnesium
Answer: C
Explanation: Ca²⁺ plays key role in excitation-contraction coupling.
91. Excess potassium in blood causes___________.
A) Hypertension
B) Arrhythmia and cardiac arrest
C) Atherosclerosis
D) Angina
Answer: B
Explanation: Hyperkalemia alters cardiac rhythm.
92. Which side of the heart is more commonly affected in heart failure?
A) Right side
B) Left side
C) Both equally
D) None
Answer: B
Explanation: Left ventricular failure → pulmonary congestion, breathlessness.
93. Stroke is caused by___________.
A) Brain hemorrhage or clot
B) Valve defect
C) Kidney failure
D) Heart enlargement
Answer: A
Explanation: Stroke occurs when brain blood supply is cut off.
94. Artificial valves are implanted in case of___________.
A) Heart attack
B) Valve stenosis or regurgitation
C) Hypertension
D) Arrhythmia
Answer: B
Explanation: Artificial valves replace defective heart valves.
95. First successful human heart transplant was performed by___________.
A) William Harvey
B) Christian Barnard
C) Ronald Ross
D) Alexander Fleming
Answer: B
Explanation: Dr. Christian Barnard performed first heart transplant in 1967 (South Africa).
96. Discovery of blood circulation was made by___________.
A) Harvey
B) Malpighi
C) Leeuwenhoek
D) Pasteur
Answer: A
Explanation: William Harvey (1628) described blood circulation.
97. Malpighi is credited with discovery of___________.
A) Heart valves
B) Capillaries
C) Red blood cells
D) Platelets
Answer: B
Explanation: Malpighi discovered capillaries, linking arteries and veins.
98. Which instrument is used to measure blood pressure?
A) Thermometer
B) Spirometer
C) Sphygmomanometer
D) ECC
Answer: C
Explanation: BP is measured in mmHg using sphygmomanometer.
99. Which heart sound is abnormal?
A) Lub
B) Dub
C) Murmur
D) None
Answer: C
Explanation: Murmurs are extra/abnormal sounds indicating valve defect.
100. Which of the following statements about human heart is true?
A) It is a voluntary muscle
B) It pumps ~5 L blood per minute
C) It has 3 chambers
D) It pumps only deoxygenated blood
Answer: B
Explanation: Heart is an involuntary four-chambered pump circulating ~5 L/min.