blood vessels

• Three types of blood vessels are arteries, veins and capillaries.
• arteries carry blood away from your heart
• capillaries are involved in the exchange of materials at the tissue
• veins carry blood to the heart
• functions of the artery

  walls are strong and elastic

  walls are thick compared to lumen

  contain thick layers of muscle
• functions of capillaries

  really small ,walls are one cell thick,

  carry blood close to every cell in the body

  have permeable walls
• functions of veins

  blood is at a lower pressure

  bigger lumen than arteries

  have valves to keep blood flow in the right direction