Understanding Blood Circulation

What is the main function of red blood cells in the circulatory system?

• To fight infections

• To transport oxygen

• To produce hormones

• To digest food

Which blood vessels carry blood away from the heart?

• Veins

• Capillaries

• Arteries

• Venules

Which chamber of the heart receives oxygen-poor blood from the body?

• Left atrium

• Right atrium

• Left ventricle

• Right ventricle

What is the main function of veins in the circulatory system?

• To carry blood away from the heart

• To carry blood towards the heart

• To filter blood

• To produce blood cells

What is the correct order of blood flow through the heart, starting from the right atrium?

• Right atrium → Right ventricle → Lungs → Left atrium → Left ventricle → Body

• Right atrium → Left atrium → Right ventricle → Left ventricle → Lungs → Body

• Right atrium → Left ventricle → Lungs → Right ventricle → Left atrium → Body

• Right atrium → Right ventricle → Left atrium → Left ventricle → Lungs → Body

Explain why arteries have thicker walls than veins.

• Because they carry blood at higher pressure

• Because they carry more blood

• Because they contain valves

• Because they are closer to the skin

Which vessel allows the exchange of oxygen and carbon dioxide between blood and tissues?

• Arteries

• Veins

• Capillaries

• Venules

Why is the left ventricle wall thicker than the right ventricle wall?

• It pumps blood to the lungs

• It pumps blood to the whole body

• It receives blood from the lungs

• It receives blood from the body

Which of the following best describes the role of haemoglobin in oxygen transport?

• It digests oxygen in the stomach

• It binds to oxygen in the lungs and releases it in tissues

• It filters oxygen in the kidneys

• It stores oxygen in the liver

A person has a blockage in a coronary artery. Predict what might happen to the heart tissue supplied by that artery.

• It will receive more oxygen

• It will receive less oxygen and may be damaged

• It will beat faster

• It will produce more blood cells