Human circulatory system MCQs With Answer for B.Pharm students offers a focused review of cardiovascular anatomy, physiology, pathophysiology and pharmacology. This concise, exam-oriented guide covers cardiac cycle dynamics, blood flow regulation, electrophysiology, vascular resistance, coagulation, biomarkers and drug mechanisms relevant to therapeutics. Keywords like cardiovascular physiology, blood circulation, cardiac output, blood pressure, anticoagulants, antiarrhythmics and B.Pharm are woven throughout to boost search visibility and learning relevance. Each question targets clinically important concepts and drug interactions to prepare pharmacy students for university exams and clinical practice. Now let’s test your knowledge with 50 MCQs on this topic.
Q1. Which structure initiates the normal electrical impulse of the heart?
- Sinoatrial (SA) node
- Atrioventricular (AV) node
- Bundle of His
- Purkinje fibers
Correct Answer: Sinoatrial (SA) node
Q2. Cardiac output is defined as which of the following formulas?
- Heart rate × Stroke volume
- Mean arterial pressure × Total peripheral resistance
- Stroke volume / Heart rate
- Systolic blood pressure − Diastolic blood pressure
Correct Answer: Heart rate × Stroke volume
Q3. Which valve prevents backflow from the left ventricle to the left atrium?
- Aortic valve
- Mitral (bicuspid) valve
- Tricuspid valve
- Pulmonary valve
Correct Answer: Mitral (bicuspid) valve
Q4. What is the primary determinant of systemic vascular resistance?
- Vessel radius
- Blood viscosity
- Blood volume
- Heart rate
Correct Answer: Vessel radius
Q5. Which phase of the cardiac cycle corresponds to ventricular relaxation and filling?
- Systole
- Isovolumetric contraction
- Diastole
- Rapid ejection
Correct Answer: Diastole
Q6. Which ECG wave represents ventricular depolarization?
- P wave
- QRS complex
- T wave
- U wave
Correct Answer: QRS complex
Q7. Starling’s law of the heart states that increased preload results in:
- Decreased contractility
- Increased stroke volume
- Increased afterload
- Decreased heart rate
Correct Answer: Increased stroke volume
Q8. Which molecule is the main endothelium-derived vasodilator?
- Nitric oxide (NO)
- Endothelin-1
- Angiotensin II
- Tromboxane A2
Correct Answer: Nitric oxide (NO)
Q9. Mean arterial pressure (MAP) is most accurately approximated by which formula?
- (Systolic + Diastolic) / 2
- Diastolic + 1/3(Systolic − Diastolic)
- Systolic − Diastolic
- Cardiac output × Heart rate
Correct Answer: Diastolic + 1/3(Systolic − Diastolic)
Q10. Which class of antiarrhythmic drugs blocks beta-adrenergic receptors?
- Class I
- Class II
- Class III
- Class IV
Correct Answer: Class II
Q11. Which lipid fraction is most strongly associated with atherogenesis?
- High-density lipoprotein (HDL)
- Low-density lipoprotein (LDL)
- Triglycerides
- Chylomicrons
Correct Answer: Low-density lipoprotein (LDL)
Q12. Digoxin primarily exerts its positive inotropic effect by inhibiting which enzyme?
- Na+/K+ ATPase
- ACE (angiotensin-converting enzyme)
- Phosphodiesterase III
- HMG-CoA reductase
Correct Answer: Na+/K+ ATPase
Q13. Which biomarker is most specific for myocardial necrosis?
- CK-MB
- Myoglobin
- Troponin I/T
- Lactate dehydrogenase (LDH)
Correct Answer: Troponin I/T
Q14. Which condition is characterized by impaired forward cardiac output and volume overload with elevated natriuretic peptides?
- Hypertrophic cardiomyopathy
- Heart failure
- Stable angina
- Essential hypertension
Correct Answer: Heart failure
Q15. Heparin acts anticoagulantly by potentiating which natural inhibitor?
- Protein C
- Antithrombin III
- Plasminogen
- Vitamin K epoxide reductase
Correct Answer: Antithrombin III
Q16. Which vessel layer contains smooth muscle and is primarily responsible for vasoconstriction?
- Tunica intima
- Tunica media
- Tunica adventitia
- Endothelium
Correct Answer: Tunica media
Q17. Which statement best describes afterload?
- Force that facilitates ventricular filling
- Pressure the ventricle must overcome to eject blood
- Volume of blood ejected per beat
- Electrical conduction delay at AV node
Correct Answer: Pressure the ventricle must overcome to eject blood
Q18. Which drug class lowers blood pressure by inhibiting angiotensin-converting enzyme?
- Beta blockers
- ACE inhibitors
- Calcium channel blockers
- Loop diuretics
Correct Answer: ACE inhibitors
Q19. Platelet aggregation is primarily mediated by which receptor-ligand interaction?
- GPIIb/IIIa binding fibrinogen
- TXA2 binding thrombin
- Factor Xa binding prothrombin
- vWF binding antithrombin
Correct Answer: GPIIb/IIIa binding fibrinogen
Q20. Which diuretic class acts on the loop of Henle producing the most potent natriuresis?
- Thiazide diuretics
- Loop diuretics
- Potassium-sparing diuretics
- Carbonic anhydrase inhibitors
Correct Answer: Loop diuretics
Q21. Which heart sound corresponds to closure of the mitral and tricuspid valves?
- S1
- S2
- S3
- S4
Correct Answer: S1
Q22. Which mechanism explains orthostatic hypotension on standing?
- Excessive sympathetic vasoconstriction
- Pooling of blood in lower extremities reducing venous return
- Increased cardiac output on standing
- Enhanced baroreceptor firing
Correct Answer: Pooling of blood in lower extremities reducing venous return
Q23. A widened QRS complex on ECG most likely indicates dysfunction in which component?
- Atrial depolarization
- Ventricular conduction system (His-Purkinje)
- SA node automaticity
- ST segment elevation
Correct Answer: Ventricular conduction system (His-Purkinje)
Q24. Which coagulation pathway is primarily assessed by prothrombin time (PT)?
- Intrinsic pathway
- Common pathway
- Extrinsic pathway
- Fibrinolytic pathway
Correct Answer: Extrinsic pathway
Q25. Vasodilation and decreased peripheral resistance are major effects of which autonomic change?
- Increased sympathetic alpha-1 activity
- Increased sympathetic beta-1 activity
- Increased parasympathetic activity to arterioles
- Reduced sympathetic vasoconstrictor tone
Correct Answer: Reduced sympathetic vasoconstrictor tone
Q26. Which condition is characterized by transmural ischemia and ST-segment elevation on ECG?
- Stable angina
- Non-ST elevation myocardial infarction (NSTEMI)
- ST-elevation myocardial infarction (STEMI)
- Pericarditis without infarction
Correct Answer: ST-elevation myocardial infarction (STEMI)
Q27. Which drug is a direct thrombin inhibitor used as an anticoagulant?
- Warfarin
- Heparin
- Dabigatran
- Clopidogrel
Correct Answer: Dabigatran
Q28. Which process dominates fluid movement from capillaries into interstitial space under normal conditions?
- Oncotic pressure exceeding hydrostatic pressure
- Hydrostatic pressure exceeding oncotic pressure at arterial end
- Lymphatic pressure forcing fluid into capillaries
- Active transport of plasma proteins out of capillaries
Correct Answer: Hydrostatic pressure exceeding oncotic pressure at arterial end
Q29. Which congenital defect creates a left-to-right shunt between ventricles?
- Atrial septal defect (ASD)
- PDA (patent ductus arteriosus)
- Ventricular septal defect (VSD)
- Coarctation of the aorta
Correct Answer: Ventricular septal defect (VSD)
Q30. Which electrolyte abnormality is most associated with digoxin toxicity and increased arrhythmia risk?
- Hyperkalemia
- Hypokalemia
- Hypermagnesemia
- Hypercalcemia
Correct Answer: Hypokalemia
Q31. Which receptor activation increases heart rate and contractility via cAMP?
- Alpha-1 adrenergic
- Beta-1 adrenergic
- Muscarinic M2
- Histamine H1
Correct Answer: Beta-1 adrenergic
Q32. Which antihypertensive class can cause a persistent dry cough as a side effect?
- Calcium channel blockers
- ACE inhibitors
- Thiazide diuretics
- Beta blockers
Correct Answer: ACE inhibitors
Q33. Which parameter decreases in left ventricular systolic heart failure?
- End-systolic volume
- Ejection fraction
- Left atrial pressure
- Natriuretic peptide levels
Correct Answer: Ejection fraction
Q34. Clopidogrel inhibits platelet aggregation by blocking which receptor pathway?
- GPIIb/IIIa receptor
- P2Y12 ADP receptor
- Thromboxane A2 synthesis
- Vitamin K-dependent clotting factors
Correct Answer: P2Y12 ADP receptor
Q35. Pulmonary circulation differs from systemic circulation mainly by having:
- Higher vascular resistance
- Lower oxygen requirement and lower pressure
- Thicker vessel walls
- Greater smooth muscle tone at rest
Correct Answer: Lower oxygen requirement and lower pressure
Q36. Which test monitoring parameter is most relevant for warfarin therapy?
- Activated partial thromboplastin time (aPTT)
- International normalized ratio (INR)
- Platelet count
- D-dimer
Correct Answer: International normalized ratio (INR)
Q37. Which pathology features lipid-laden macrophages and a fibrous cap in arterial intima?
- Arteriosclerosis obliterans
- Atherosclerotic plaque
- Monckeberg medial calcific sclerosis
- Vasculitis
Correct Answer: Atherosclerotic plaque
Q38. Which drug lowers afterload by direct arteriolar vasodilation and is used in heart failure?
- Hydralazine
- Spironolactone
- Propranolol
- Furosemide
Correct Answer: Hydralazine
Q39. Which hormone acts to increase sodium reabsorption and potassium excretion in the kidney?
- Aldosterone
- ANP (atrial natriuretic peptide)
- BNP (brain natriuretic peptide)
- ADH (vasopressin)
Correct Answer: Aldosterone
Q40. Which clinical sign suggests right-sided heart failure?
- Pulmonary edema
- Peripheral edema and jugular venous distension
- Orthopnea
- Basilar crackles on lung auscultation
Correct Answer: Peripheral edema and jugular venous distension
Q41. ACE inhibitors reduce blood pressure mainly by decreasing production of which peptide?
- Bradykinin
- Angiotensin II
- Aldosterone
- Nitric oxide
Correct Answer: Angiotensin II
Q42. Tissue plasminogen activator (tPA) promotes thrombolysis by converting plasminogen to:
- Thrombin
- Plasmin
- Fibrinogen
- Factor XIII
Correct Answer: Plasmin
Q43. Which arrhythmia is characterized by chaotic atrial electrical activity and an irregularly irregular ventricular response?
- Atrial flutter
- Atrial fibrillation
- Ventricular tachycardia
- Sinus bradycardia
Correct Answer: Atrial fibrillation
Q44. Which measurement technique uses Korotkoff sounds?
- ECG
- Continuous arterial line
- Oscillometric ambulatory monitor
- Sphygmomanometer (auscultatory blood pressure)
Correct Answer: Sphygmomanometer (auscultatory blood pressure)
Q45. Lipoprotein lipase deficiency primarily leads to accumulation of which lipid in plasma?
- High-density lipoprotein (HDL)
- Low-density lipoprotein (LDL)
- Chylomicrons (triglyceride-rich)
- Small dense LDL
Correct Answer: Chylomicrons (triglyceride-rich)
Q46. The major effect of nitrates in angina management is:
- Increasing myocardial oxygen demand
- Venodilation reducing preload and myocardial oxygen consumption
- Blocking beta receptors in the heart
- Inhibiting calcium influx into vascular smooth muscle only
Correct Answer: Venodilation reducing preload and myocardial oxygen consumption
Q47. Which biochemical change is expected in iron deficiency anemia?
- Elevated ferritin and high MCV
- Low ferritin and low hemoglobin with microcytosis
- Normal ferritin with macrocytosis
- High transferrin saturation
Correct Answer: Low ferritin and low hemoglobin with microcytosis
Q48. Which physiologic reflex reduces blood pressure when arterial baroreceptors detect increased stretch?
- Increased sympathetic output and vasoconstriction
- Decreased parasympathetic tone to heart
- Increased parasympathetic and decreased sympathetic activity causing bradycardia and vasodilation
- Activation of RAAS to increase blood volume
Correct Answer: Increased parasympathetic and decreased sympathetic activity causing bradycardia and vasodilation
Q49. Which pharmacologic agent is primarily used to acutely lower BP by rapid vasodilation and is administered intravenously in hypertensive emergencies?
- Nitroprusside
- Lisinopril orally
- Hydrochlorothiazide
- Atenolol orally
Correct Answer: Nitroprusside
Q50. Which serum change is typically seen during acute myocardial infarction within 3–6 hours?
- Rapid rise in troponin I/T
- Immediate rise in ESR only
- Decrease in CK-MB with no troponin change
- Sharp fall in serum potassium
Correct Answer: Rapid rise in troponin I/T
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