Blood & Circulatory System MCQs 2026

What are the two upper chambers of the heart called

1. AVentricles✓
2. BAtria✓
3. CValves✓
4. DSepta✓

What are the two large veins that return deoxygenated blood to the heart from the upper and lower body called

1. APulmonary veins✓
2. BVena cava (superior and inferior)✓
3. CCoronary veins✓
4. DRenal veins✓

What is the largest artery in the human body, carrying oxygenated blood from the heart to the body

1. APulmonary artery✓
2. BAorta✓
3. CVena cava✓
4. DCoronary artery✓

Which blood vessel carries oxygenated blood from the lungs back to the heart, an exception to typical vein function

1. AAorta✓
2. BPulmonary artery✓
3. CPulmonary vein✓
4. DVena cava✓

What are the two lower chambers of the heart called

1. AVentricles✓
2. BAtria✓
3. CValves✓
4. DSepta✓

What is the term for the tiny, thin-walled blood vessels where gas and nutrient exchange occurs with tissues

1. AArteries✓
2. BVeins✓
3. CCapillaries✓
4. DVenules✓

What is the term for blood vessels that carry blood back toward the heart

1. AArteries✓
2. BVeins✓
3. CCapillaries✓
4. DArterioles✓

What is the term for blood vessels that carry blood away from the heart

1. AArteries✓
2. BVeins✓
3. CCapillaries✓
4. DVenules✓

What structures within the heart prevent the backward flow of blood between chambers

1. AValves✓
2. BSepta✓
3. CNodes✓
4. DArteries✓

What is the name of the heart valve located between the right atrium and right ventricle

1. ATricuspid valve✓
2. BMitral valve✓
3. CAortic valve✓
4. DPulmonary valve✓

What is the name of the heart valve located between the left atrium and left ventricle

1. ATricuspid valve✓
2. BMitral (Bicuspid) valve✓
3. CAortic valve✓
4. DPulmonary valve✓

What structure serves as the heart's natural pacemaker, initiating each heartbeat

1. ASinoatrial (SA) node✓
2. BAtrioventricular (AV) node✓
3. CBundle of His✓
4. DPurkinje fibers✓

What structure receives the electrical signal from the SA node and relays it to the ventricles

1. ASinoatrial (SA) node✓
2. BAtrioventricular (AV) node✓
3. CBundle of His (part of the relay pathway)✓
4. DPurkinje fibers (part of the relay pathway)✓

What is the term for the network of blood vessels supplying oxygen-rich blood specifically to the heart muscle itself

1. APulmonary circulation✓
2. BCoronary circulation✓
3. CSystemic circulation✓
4. DPortal circulation✓

What is the term for the circulatory pathway carrying blood between the heart and lungs

1. APulmonary circulation✓
2. BCoronary circulation✓
3. CSystemic circulation✓
4. DPortal circulation✓

What is the term for the circulatory pathway carrying blood between the heart and the rest of the body

1. APulmonary circulation✓
2. BCoronary circulation✓
3. CSystemic circulation✓
4. DPortal circulation✓

What percentage of blood volume is typically composed of plasma

1. AAbout 25%✓
2. BAbout 55%✓
3. CAbout 75%✓
4. DAbout 90%✓

What percentage of blood cells in whole blood are typically red blood cells

1. AAbout 25%✓
2. BAbout 45%✓
3. CAbout 70%✓
4. DAbout 99%✓

What is the medical term for the percentage of blood volume occupied by red blood cells

1. AHemoglobin count✓
2. BHematocrit✓
3. CWhite blood cell count✓
4. DPlatelet count✓

What is the average lifespan of a red blood cell in the human body

1. AAbout 10 days✓
2. BAbout 120 days✓
3. CAbout 1 year✓
4. DAbout 5 years✓

Where are red blood cells primarily broken down after reaching the end of their lifespan

1. AKidneys✓
2. BSpleen and liver✓
3. CLungs✓
4. DPancreas✓

What term describes white blood cells that engulf and destroy pathogens through a process called phagocytosis

1. ALymphocytes (a different type)✓
2. BPhagocytes (including neutrophils and macrophages)✓
3. CPlatelets✓
4. DErythrocytes✓

Which type of white blood cell is specifically responsible for producing antibodies as part of the immune response

1. ANeutrophils✓
2. BLymphocytes (specifically B-lymphocytes)✓
3. CPlatelets✓
4. DErythrocytes✓

What are proteins produced by the immune system to specifically target and neutralize foreign pathogens called

1. AHormones✓
2. BAntibodies✓
3. CEnzymes✓
4. DHemoglobin✓

What is the term for the process by which the body develops immunity through exposure to a pathogen or vaccine

1. AImmunization✓
2. BSterilization✓
3. CPasteurization✓
4. DFermentation✓

Which blood vessel carries deoxygenated blood from the heart to the lungs, an exception to typical artery function

1. AAorta✓
2. BPulmonary artery✓
3. CPulmonary vein✓
4. DVena cava✓

What term describes immunity gained through the body's own immune response after infection or vaccination

1. AActive immunity✓
2. BPassive immunity✓
3. CInnate immunity (different concept)✓
4. DHerd immunity (population-level concept)✓

What term describes immunity gained through the transfer of antibodies from another source, such as from mother to infant

1. AActive immunity✓
2. BPassive immunity✓
3. CInnate immunity✓
4. DHerd immunity✓

What term describes indirect protection from infectious disease that occurs when a large portion of a population becomes immune

1. AActive immunity✓
2. BPassive immunity✓
3. CInnate immunity✓
4. DHerd immunity✓

What is the general term for the body's defense system against pathogens and disease

1. ACirculatory system✓
2. BImmune system✓
3. CEndocrine system✓
4. DNervous system✓

What is the term for the tiny mesh tube inserted into a narrowed artery to help keep it open after angioplasty

1. AStent✓
2. BPacemaker✓
3. CCatheter (broader term)✓
4. DDefibrillator✓

What is the term for the branch of immunity that develops over time and targets specific pathogens

1. AInnate immunity✓
2. BAdaptive (Acquired) immunity✓
3. CPassive immunity (subset concept)✓
4. DHerd immunity✓

What term describes the body's ability to "remember" a pathogen after initial exposure, allowing faster response upon re-exposure

1. AImmunological memory✓
2. BPassive immunity✓
3. CInnate immunity✓
4. DHerd immunity✓

What specialized white blood cells specifically target and destroy cells infected with viruses or cancerous cells

1. AB-lymphocytes✓
2. BT-lymphocytes (specifically cytotoxic T-cells)✓
3. CPlatelets✓
4. DNeutrophils✓

Which type of blood cell fragment plays a crucial role in blood clotting

1. ARed blood cells✓
2. BWhite blood cells✓
3. CPlatelets✓
4. DPlasma proteins (general)✓

What is the term for the process by which blood clots to prevent excessive bleeding after injury

1. ACoagulation✓
2. BHemolysis✓
3. CDiapedesis✓
4. DVasodilation✓

What is the term for the destruction or breakdown of red blood cells, releasing hemoglobin

1. ACoagulation✓
2. BHemolysis✓
3. CDiapedesis✓
4. DVasoconstriction✓

What is the term for blood vessels narrowing, reducing blood flow, often in response to cold or injury

1. AVasodilation✓
2. BVasoconstriction✓
3. CDiapedesis✓
4. DHemolysis✓

What is the term for blood vessels widening, increasing blood flow, often in response to heat or exercise

1. AVasodilation✓
2. BVasoconstriction✓
3. CDiapedesis✓
4. DHemolysis✓

Which protein found in blood plasma plays a crucial role in maintaining osmotic pressure and transporting substances

1. AHemoglobin✓
2. BAlbumin✓
3. CMyoglobin✓
4. DKeratin✓

Which protein, found in muscle tissue, stores oxygen for use during muscle contraction, distinct from hemoglobin

1. AAlbumin✓
2. BMyoglobin✓
3. CCollagen✓
4. DKeratin✓

What is the term for the medical procedure involving the transfer of blood or blood products from a donor to a recipient

1. ADialysis✓
2. BBlood transfusion✓
3. CBiopsy✓
4. DEndoscopy✓

Why is blood type compatibility crucial before performing a blood transfusion

1. AIncompatible blood types can trigger dangerous immune reactions✓
2. BBlood type has no medical significance✓
3. CAll blood types are always compatible✓
4. DOnly Rh factor matters, not ABO type✓

What condition can occur if an Rh-negative mother carries an Rh-positive fetus, particularly in subsequent pregnancies without treatment

1. ARh incompatibility (Hemolytic disease of the newborn)✓
2. BSickle cell disease✓
3. CHemophilia✓
4. DThalassemia✓

What medical treatment is commonly given to Rh-negative mothers to prevent Rh incompatibility complications in future pregnancies

1. ARhoGAM injection✓
2. BInsulin injection✓
3. CAntibiotic treatment✓
4. DBlood transfusion (not the specific preventive treatment)✓

What is the medical term for high levels of cholesterol in the blood, a risk factor for cardiovascular disease

1. AHypercholesterolemia✓
2. BHypocholesterolemia✓
3. CHyperglycemia✓
4. DHypoglycemia✓

What is the medical term for high blood sugar levels, commonly associated with diabetes

1. AHyperglycemia✓
2. BHypoglycemia✓
3. CHypercholesterolemia✓
4. DHypercalcemia✓

What is the medical term for low blood sugar levels, which can cause symptoms like dizziness and confusion

1. AHyperglycemia✓
2. BHypoglycemia✓
3. CHypercalcemia✓
4. DHyponatremia✓

What is the general term for a comprehensive blood test that measures various blood components, commonly used in routine health checks

1. AComplete Blood Count (CBC)✓
2. BElectrocardiogram (ECG)✓
3. CBiopsy✓
4. DMRI scan✓

What medical device measures the electrical activity of the heart over time, producing a graphical readout

1. ASphygmomanometer✓
2. BElectrocardiograph (ECG/EKG)✓
3. CStethoscope✓
4. DEndoscope✓

What is the medical term for an irregular heartbeat, which can range from harmless to serious

1. AArrhythmia✓
2. BTachycardia (a specific type)✓
3. CBradycardia (a specific type)✓
4. DAngina (different condition)✓

What is the medical term for chest pain caused by reduced blood flow to the heart muscle

1. AAngina✓
2. BArrhythmia✓
3. CMyocardial infarction (heart attack, more severe)✓
4. DAneurysm✓

What is the general medical term for diseases affecting the heart and blood vessels

1. ACardiovascular disease✓
2. BRespiratory disease✓
3. CNeurological disease✓
4. DMusculoskeletal disease✓

What lifestyle factor is most strongly and consistently linked to increased cardiovascular disease risk

1. ARegular moderate exercise (reduces risk)✓
2. BSmoking✓
3. CAdequate sleep (reduces risk)✓
4. DBalanced diet (reduces risk)✓

What medical procedure involves widening narrowed or blocked coronary arteries, often using a balloon and stent

1. ABypass surgery (alternative procedure)✓
2. BAngioplasty✓
3. CDialysis✓
4. DBiopsy✓

What is the term for the branch of immunity present from birth, providing a general, non-specific defense

1. AInnate immunity✓
2. BAdaptive immunity✓
3. CPassive immunity✓
4. DHerd immunity✓

What surgical procedure creates a new pathway around a blocked coronary artery, often using a graft from another blood vessel

1. AAngioplasty (alternative procedure)✓
2. BCoronary bypass surgery✓
3. CDialysis✓
4. DBiopsy✓

What is the term for the medical specialty focused on diagnosing and treating heart rhythm disorders specifically

1. AGeneral cardiology✓
2. BElectrophysiology✓
3. CNephrology✓
4. DEndocrinology✓

What device can be surgically implanted to help regulate an abnormally slow or irregular heartbeat

1. APacemaker✓
2. BStent✓
3. CCatheter✓
4. DDefibrillator (different, though related, device)✓

What medical device delivers an electric shock to restore normal heart rhythm during certain life-threatening arrhythmias

1. APacemaker (different function)✓
2. BDefibrillator✓
3. CStent (different function)✓
4. DCatheter (different function)✓