Blood Vessels

• What do arteries do + their features

  carry blood away from the heart to the body.

  thick elastic fibres allow them to stretch, this helps the vessels withstand the high pressure created by the pumping of the heart.

  layers of muscle in the walls make them strong
• what do veins do + their features

  carry blood towards ( INto) the heart

  wide lumen- to allow the low pressure blood to flow through

  they have valves to ensure the blood flows in the right direction
• what do capillaries do + their features

  allow the blood to flow very close to cells to enable substances to move between them

  one cell thick walls create a short diffusion pathway

  permeable walls so substances can move diffuse across them