Blood & Circulatory System MCQs 2026

What are the two upper chambers of the heart called

1. A Ventricles ✓
2. B Atria ✓
3. C Valves ✓
4. D Septa ✓

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

1. A Pulmonary veins ✓
2. B Vena cava (superior and inferior) ✓
3. C Coronary veins ✓
4. D Renal veins ✓

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

1. A Pulmonary artery ✓
2. B Aorta ✓
3. C Vena cava ✓
4. D Coronary artery ✓

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

1. A Aorta ✓
2. B Pulmonary artery ✓
3. C Pulmonary vein ✓
4. D Vena cava ✓

What are the two lower chambers of the heart called

1. A Ventricles ✓
2. B Atria ✓
3. C Valves ✓
4. D Septa ✓

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

1. A Arteries ✓
2. B Veins ✓
3. C Capillaries ✓
4. D Venules ✓

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

1. A Arteries ✓
2. B Veins ✓
3. C Capillaries ✓
4. D Arterioles ✓

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

1. A Arteries ✓
2. B Veins ✓
3. C Capillaries ✓
4. D Venules ✓

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

1. A Valves ✓
2. B Septa ✓
3. C Nodes ✓
4. D Arteries ✓

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

1. A Tricuspid valve ✓
2. B Mitral valve ✓
3. C Aortic valve ✓
4. D Pulmonary valve ✓

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

1. A Tricuspid valve ✓
2. B Mitral (Bicuspid) valve ✓
3. C Aortic valve ✓
4. D Pulmonary valve ✓

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

1. A Sinoatrial (SA) node ✓
2. B Atrioventricular (AV) node ✓
3. C Bundle of His ✓
4. D Purkinje fibers ✓

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

1. A Sinoatrial (SA) node ✓
2. B Atrioventricular (AV) node ✓
3. C Bundle of His (part of the relay pathway) ✓
4. D Purkinje 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. A Pulmonary circulation ✓
2. B Coronary circulation ✓
3. C Systemic circulation ✓
4. D Portal circulation ✓

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

1. A Pulmonary circulation ✓
2. B Coronary circulation ✓
3. C Systemic circulation ✓
4. D Portal circulation ✓

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

1. A Pulmonary circulation ✓
2. B Coronary circulation ✓
3. C Systemic circulation ✓
4. D Portal circulation ✓

What percentage of blood volume is typically composed of plasma

1. A About 25% ✓
2. B About 55% ✓
3. C About 75% ✓
4. D About 90% ✓

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

1. A About 25% ✓
2. B About 45% ✓
3. C About 70% ✓
4. D About 99% ✓

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

1. A Hemoglobin count ✓
2. B Hematocrit ✓
3. C White blood cell count ✓
4. D Platelet count ✓

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

1. A About 10 days ✓
2. B About 120 days ✓
3. C About 1 year ✓
4. D About 5 years ✓

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

1. A Kidneys ✓
2. B Spleen and liver ✓
3. C Lungs ✓
4. D Pancreas ✓

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

1. A Lymphocytes (a different type) ✓
2. B Phagocytes (including neutrophils and macrophages) ✓
3. C Platelets ✓
4. D Erythrocytes ✓

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

1. A Neutrophils ✓
2. B Lymphocytes (specifically B-lymphocytes) ✓
3. C Platelets ✓
4. D Erythrocytes ✓

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

1. A Hormones ✓
2. B Antibodies ✓
3. C Enzymes ✓
4. D Hemoglobin ✓

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

1. A Immunization ✓
2. B Sterilization ✓
3. C Pasteurization ✓
4. D Fermentation ✓

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

1. A Aorta ✓
2. B Pulmonary artery ✓
3. C Pulmonary vein ✓
4. D Vena cava ✓

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

1. A Active immunity ✓
2. B Passive immunity ✓
3. C Innate immunity (different concept) ✓
4. D Herd immunity (population-level concept) ✓

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

1. A Active immunity ✓
2. B Passive immunity ✓
3. C Innate immunity ✓
4. D Herd immunity ✓

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

1. A Active immunity ✓
2. B Passive immunity ✓
3. C Innate immunity ✓
4. D Herd immunity ✓

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

1. A Circulatory system ✓
2. B Immune system ✓
3. C Endocrine system ✓
4. D Nervous system ✓

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

1. A Stent ✓
2. B Pacemaker ✓
3. C Catheter (broader term) ✓
4. D Defibrillator ✓

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

1. A Innate immunity ✓
2. B Adaptive (Acquired) immunity ✓
3. C Passive immunity (subset concept) ✓
4. D Herd immunity ✓

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

1. A Immunological memory ✓
2. B Passive immunity ✓
3. C Innate immunity ✓
4. D Herd immunity ✓

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

1. A B-lymphocytes ✓
2. B T-lymphocytes (specifically cytotoxic T-cells) ✓
3. C Platelets ✓
4. D Neutrophils ✓

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

1. A Red blood cells ✓
2. B White blood cells ✓
3. C Platelets ✓
4. D Plasma proteins (general) ✓

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

1. A Coagulation ✓
2. B Hemolysis ✓
3. C Diapedesis ✓
4. D Vasodilation ✓

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

1. A Coagulation ✓
2. B Hemolysis ✓
3. C Diapedesis ✓
4. D Vasoconstriction ✓

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

1. A Vasodilation ✓
2. B Vasoconstriction ✓
3. C Diapedesis ✓
4. D Hemolysis ✓

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

1. A Vasodilation ✓
2. B Vasoconstriction ✓
3. C Diapedesis ✓
4. D Hemolysis ✓

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

1. A Hemoglobin ✓
2. B Albumin ✓
3. C Myoglobin ✓
4. D Keratin ✓

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

1. A Albumin ✓
2. B Myoglobin ✓
3. C Collagen ✓
4. D Keratin ✓

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

1. A Dialysis ✓
2. B Blood transfusion ✓
3. C Biopsy ✓
4. D Endoscopy ✓

Why is blood type compatibility crucial before performing a blood transfusion

1. A Incompatible blood types can trigger dangerous immune reactions ✓
2. B Blood type has no medical significance ✓
3. C All blood types are always compatible ✓
4. D Only 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. A Rh incompatibility (Hemolytic disease of the newborn) ✓
2. B Sickle cell disease ✓
3. C Hemophilia ✓
4. D Thalassemia ✓

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

1. A RhoGAM injection ✓
2. B Insulin injection ✓
3. C Antibiotic treatment ✓
4. D Blood 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. A Hypercholesterolemia ✓
2. B Hypocholesterolemia ✓
3. C Hyperglycemia ✓
4. D Hypoglycemia ✓

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

1. A Hyperglycemia ✓
2. B Hypoglycemia ✓
3. C Hypercholesterolemia ✓
4. D Hypercalcemia ✓

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

1. A Hyperglycemia ✓
2. B Hypoglycemia ✓
3. C Hypercalcemia ✓
4. D Hyponatremia ✓

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

1. A Complete Blood Count (CBC) ✓
2. B Electrocardiogram (ECG) ✓
3. C Biopsy ✓
4. D MRI scan ✓

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

1. A Sphygmomanometer ✓
2. B Electrocardiograph (ECG/EKG) ✓
3. C Stethoscope ✓
4. D Endoscope ✓

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

1. A Arrhythmia ✓
2. B Tachycardia (a specific type) ✓
3. C Bradycardia (a specific type) ✓
4. D Angina (different condition) ✓

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

1. A Angina ✓
2. B Arrhythmia ✓
3. C Myocardial infarction (heart attack, more severe) ✓
4. D Aneurysm ✓

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

1. A Cardiovascular disease ✓
2. B Respiratory disease ✓
3. C Neurological disease ✓
4. D Musculoskeletal disease ✓

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

1. A Regular moderate exercise (reduces risk) ✓
2. B Smoking ✓
3. C Adequate sleep (reduces risk) ✓
4. D Balanced diet (reduces risk) ✓

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

1. A Bypass surgery (alternative procedure) ✓
2. B Angioplasty ✓
3. C Dialysis ✓
4. D Biopsy ✓

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

1. A Innate immunity ✓
2. B Adaptive immunity ✓
3. C Passive immunity ✓
4. D Herd immunity ✓

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

1. A Angioplasty (alternative procedure) ✓
2. B Coronary bypass surgery ✓
3. C Dialysis ✓
4. D Biopsy ✓

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

1. A General cardiology ✓
2. B Electrophysiology ✓
3. C Nephrology ✓
4. D Endocrinology ✓

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

1. A Pacemaker ✓
2. B Stent ✓
3. C Catheter ✓
4. D Defibrillator (different, though related, device) ✓

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

1. A Pacemaker (different function) ✓
2. B Defibrillator ✓
3. C Stent (different function) ✓
4. D Catheter (different function) ✓