Circulartory System- Blood Vessles

Question 1

what is the role of the arteries?

Answer 1

they carry blood away from the heart

Question 2

what is the role of the capillaries ?

Answer 2

•they carry blood really close to every cell in the body to exchange substances with them
•they supply food and oxygen and take away waste like carbon dioxide

Question 3

what is the role of the veins?

Answer 3

these carry the blood to the heart

Question 4

what are the features of the artery?

Answer 4

•the heart pumps blood at high pressure so their walls are strong and elastic
•the walls are thick compared to the size of the lumen
•they contain thick layers of muscle to make them strong and elastic fibres to allow them to stretch and spring back

Question 5

what are the features of the capillaries?

Answer 5

•they are tiny (too small to see)
• they have permeable walls so substances can diffuse in and out
•their walls are only usually one cell thick which increases the rate of diffusion by decreasing the distance over which it occurs

Question 6

what are the features of the veins?

Answer 6

•they have bigger lumen than arteries to help blood flow
•the blood is at lower pressure in veins so the walls don’t need to be as thick as arteries
•they also have valves to prevent backflow