B5 Blood Vessels

Question 1

List the three main types of blood vessel

Answer 1

Arteries
Capillaries
Veins

Question 2

What do arteries do?

Answer 2

Carry blood away from the heart

Question 3

What do capillaries do?

Answer 3

These are involved in the exchange of materials at the tissues

Question 4

What do veins do?

Answer 4

Carry the blood to the heart

Question 5

What are arteries walls like?

Answer 5

Strong and elastic

Question 6

Why are artery walls strong and elastic?

Answer 6

Because the heart pumps the blood out at high pressure.

Question 7

What is the lumen?

Answer 7

The hole down the middle of the blood vessel

Question 8

Complete this sentence

The walls of arteries are …… compared to the size of the lumen.

Answer 8

Thick

Question 9

What do arteries contain to make them strong?

Answer 9

Muscle

Question 10

What do arteries contain to allow them to stretch and spring back?

Answer 10

Elastic fibres

Question 11

Complete the sentence

The capillaries are really ……

Answer 11

Tiny

Question 12

What are networks of capillaries in tissue called?

Answer 12

Capillary beds

Question 13

What do capillaries do?

Answer 13

They carry the blood really close to every cell in the body to exchange substances with them.

Question 14

Why do capillaries have permeable walls?

Answer 14

So substances can diffuse in and out

Question 15

What do capillaries supply?

Answer 15

Food and oxygen

Question 16

What do capillaries take away?

Answer 16

Waste like CO2

Question 17

Why are capillary walls usually only one cell thick?

Answer 17

Thin walls increase the rate of diffusion by decreasing the distance over which it occurs.

Question 18

Why are vein walls thinner than artery walls?

Answer 18

The blood in them is at a lower pressure.

Question 19

Why do veins have a bigger lumen than arteries?

Answer 19

To help the blood flow despite the lower pressure.

Question 20

What helps to keep the blood in veins flowing in the right direction?

Answer 20

Valves

Question 21

What are the muscle and elastic fibres like in veins?

Answer 21

Thin layers of elastic fibres and smooth muscle

Question 22

Describe how veins are adapted to carry blood back to the heart (2 marks)

Answer 22

They have big lumen to help the blood flow despite the low pressure (1 mark)

And they have valves to keep the blood flowing in the right direction (1 mark)

Question 23

Explain how capillaries are adapted to their function. (3 marks)

Answer 23

Networks of capillaries carry blood to every cell in the body to exchange substances with them (1 mark)

They have permeable walls, so that substances can easily diffuse in and out of them (1 mark)

Their walls are only one cell thick, which increases the rate of diffusion (1 mark)