Circulatory System & Lymphatic system Quiz

Which layer of the heart wall is primarily responsible for contraction?

• Endocardium

• Myocardium

• Pericardium

• Epicardium

During ventricular systole, what prevents backflow into the atria?

• Semilunar valves

• AV valves (tricuspid/bicuspid)

• Purkinje fibers

• Chordae tendineae

A blockage in the coronary arteries would directly impair blood supply to which structure?

• Lungs

• Heart muscle

• Liver

• Brain

Which blood vessel type has the thickest tunica media to withstand high pressure?

• Vein

• Capillary

• Artery

• Venule

If the SA node fails, what is the most likely immediate effect?

• Increased heart rate

• Uncoordinated ventricular contractions

• Cessation of heartbeat

• No effect; AV node takes over

Which condition results from fatty deposits hardening arterial walls?

• Pulmonary embolism

• Atherosclerosis

• Elephantiasis

• Tonsillitis

Why does blood pressure decrease as it moves from arteries to veins?

• Increased vessel diameter

• Loss of plasma to tissues

• Peripheral resistance smoothing pressure surges

• Valves in veins

A patient with pulmonary hypertension would likely exhibit:

• Low blood O₂ levels

• Decreased right ventricle workload

• High systemic blood pressure

• Reduced lymph flow

Which phase of the cardiac cycle corresponds to ventricular filling?

• Atrial systole

• Ventricular systole

• Early diastole

• Late diastole

What is the primary role of capillaries?

• Transport blood to the heart

• Exchange gases/nutrients with tissues

• Store oxygenated blood

• Filter pathogens