Circulatory system - blood vessels

Question 1

name and describe the three types of blood vessels

Answer 1

arteries - carry blood away from the heart
capillaries - involved in the exchange of materials at the tissues
veins - carry blood to the heart

Question 2

how do the arteries carry blood under pressure

Answer 2

heart pumps blood out at a high pressure so the artery walls are strong and elastic and thick compared to the size of the hole down the middle and contain layers muscle and elastic fibres

Question 3

how do capillaries carry blood

Answer 3

they have permeable walls, so substances can diffuse in and out
they supply food and oxygen and take away waste
only one cell thick which increases rate of diffusion by decreasing the distance in which it occurs

Question 4

how do veins take blood back to the heart

Answer 4

capillaries join up to form veins, the blood is at a low pressure so the walls don’t need to be thick. they do have a bigger lumen though
they have valves to keep the blood going in the right direction

Question 5

what is the equation for the rate of blood flow

Answer 5

volume of blood / number of minutes