Blood vessels

The diagram shows cross-sections of three types of blood vessel, not drawn to the same scale.

What are X, Y and Z?

• X : artery; Y : capillary; Z : vein

• X : artery; Y : vein; Z : capillary

• X : vein; Y : artery; Z : capillary

• X : vein; Y : capillary; Z : artery

The diagram shows a valve in a section through a blood vessel.

Which statement is correct?

• Blood flows from X to Y, opening the valve.

• Muscles in the wall contract and close the valve, preventing backflow.

• The elastic wall causes the valve to close between heartbeats.

• The valve is forced open when the blood pressure at Y is greater than at X.

The coronary arteries carry blood to the ..................

• brain tissue

• heart muscle

• liver cells

• alveolar walls

The diagram shows the circulatory system. Which vessel must the blood pass through in flowing from X to Y?

• hepatic artery

• hepatic portal vein

• pulmonary artery

• renal vein

An exchange of nutrients and wastes takes place across ................. walls.

• artery

• vein

• capillary

Valves allow blood to flow .................

• away from the heart and limit high blood pressure in tissues

• to those capillary beds that need the blood at that moment

• toward the heart in veins that lack significant blood pressure

• to the lungs when the blood lacks enough oxygen

The .................... arteries are extremely important because they serve the heart muscle itself.

• cardiac

• coronary

• pulmonary

The two-way exchange of substances between blood and body cells occurs only through

• arterioles

• capillaries

• venules

How many times does a red blood cell pass through the heart on a journey from the renal artery to the aorta?

• once

• twice

• thrice

• many times

What is the name of the blood vessel carrying oxygenated blood directly to the liver?

• hepatic portal vein

• hepatic artery

• hepatic vein

• vena cava