Blood vessels

• Vein ➡️ into the heart, deoxygenated blood
• Artery ➡️ away from the heart, oxygenated oxygen
• Types of blood vessels:

  • Artery
  • Vein
  • Capillary
• Arteries

  • layers of muscle in the walls makes them strong
  • elastic fibres allow them to stretch
  • this helps the artery withstand the high pressure created by the heart
• Veins

  • lumen is wide to allow the low pressure blood to flow through
  • have valves to ensure the blood flows in the right direction
• Capillaries

  • one cell thick walls, for short diffusion path
  • permeable walls, so substance can move across
• blood vessels

  A) Lumen

  B) Fibrous coats

  C) Endothelium

  D) Elastic fibres and smooth muscle

  E) Vein

  F) Artery