Circulatory System - Blood Vessels

Question 1

What are the three types of blood vessels and what do they do?

Answer 1

1) arteries - carry blood away from the heart under high pressure
2) capillaries - involved in the exchange of materials at the tissues
3) veins - carry blood to the heart

Question 2

What features do arteries have and why? (3 points)

Answer 2

1) pumps blood at high pressure so the walls are strong and elastic
2) thick walls compared to lumen (hole down the centre)
3) thick layers of muscle so they are strong, and elastic fibres so they can stretch and spring back

Question 3

What features do capillaries have and why? (4 points)

Answer 3

1) carry blood close to every cell in the body to exchange substances with them
2) permeable walls for diffusion
3) supply food and oxygen, and take away waste like CO2
4) thin cell walls (one cell thick) so diffusion rate is increased as there is a shorter diffusion distance

Question 4

What features do veins have and why? (3 points)

Answer 4

1) lower pressure than arteries so thinner walls
2) bigger lumen to help blood flow despite the lower pressure
3) valves to help blood flow in the right direction