The Human Circulatory System Quiz

Which blood vessel has walls that are only one cell thick?

• Capillaries

• Veins

• Arterioles

• Arteries

Why do veins have valves?

• To prevent blood from flowing backward

• To increase blood pressure

• To allow nutrients to pass through

• To make the blood flow faster

What is the primary function of capillaries in the circulatory system?

• Carry deoxygenated blood back to the heart

• Exchange nutrients and gases with tissues

• Store blood for emergencies

• Transport blood from the heart to organs

What is the role of arterioles in the circulatory system?

• They connect arteries to veins

• They transport blood from capillaries to veins

• They are the smallest branches of arteries

• They store oxygenated blood

How do venules contribute to blood circulation?

• They connect capillaries to veins

• They carry blood away from the heart

• They regulate blood pressure

• They transport oxygenated blood to tissues