Blood vessels

Question 1

What are the 4 types of blood vessels?

Answer 1

Arteries, veins, arterioles, capillaries.

Question 2

Do arteries carry blood to the heart and away from the heart?

Answer 2

Arteries carry blood away from the heart and into arterioles.

Question 3

What are arterioles?

Answer 3

They are smaller than arteries and connect to capillaries.

Question 4

What are capillaries?

Answer 4

They connect the arterioles to the veins.

Question 5

What are veins?

Answer 5

Carry blood back into the heart.

Question 6

Describe the difference of muscle layer between arteries and veins.

Answer 6

Arteries = Thicker than veins so constriction and dilation can occur to control the volume of blood.
Veins = Relatively thin so it cannot control the blood flow.

Question 7

Describe the difference in elastic layers between arteries and veins.

Answer 7

Arteries = Thicker than veins to help maintain blood pressure. The walls can stretch and recoil in response to the heartbeat.
Veins = Relatively thin as the pressure is much lower.

Question 8

Describe the difference in wall thickness between arteries and veins.

Answer 8

Arteries = Have thicker walls than veins to help prevent the vessels from bursting due to the high pressure.
Veins = Thin as the pressure is much lower so there is a low risk of bursting. The thinness means the vessels are easily flattened, which helps the flow of blood up to the heart.

Question 9

Describe the difference in valves between arteries and veins.

Answer 9

• Arteries don’t have valves
• Veins do have valves

Question 10

Describe capillaries.

Answer 10

Capillaries form capillary beds as exchange surfaces, which are formed from many branched capillaries. These all have a narrow diameter to slow blood flow. Red blood cells can only just fit through and are squished against the walls, this maximizes diffusion.

Question 11

Describe the structure of the muscle layer in arterioles.

Answer 11

Thicker than in arteries to restrict blood flow to the capillaries.

Question 12

Describe the structure of the elastic layer in arterioles

Answer 12

Thinner than in arterioles as the pressure is lower.

Question 13

Describe the wall thickness of arterioles,

Answer 13

Thinner as pressure is slightly lower.

Question 14

Do arterioles have valves?

Answer 14

No

Question 15

Do capillaries have a muscle layer, elastic layer or valves?

Answer 15

No

Question 16

Describe the muscle thickness of capillaries.

Answer 16

One cell thick consisting of only a lining layer. This provides a short diffusion distance for exchanging materials between the blood and the cells.