Blood vessels

• Direction of blood flow in artery?

  Away from heart
• Direction of blood flow in vein?

  Towards the heart
• Direction of blood flow in the capillaries?

  From arteries to veins
• Thickness of artery wall?

  Thick. Contains muscle for high blood pressure. Contains elastics fibres, for pushing blood through.
• Thickness of vein wall?

  Thinner than artery. Less muscle and fewer elastic fibres.
• Thickness of capillary wall?

  One cell thick to allow for gas exchange
• Blood pressure in artery?

  High
• Blood pressure in vein?

  Low
• Blood pressure in capillaries?

  Low
• Are there valves in arteries?

  No
• Lumen diameter in artery?

  Relatively small
• Are there valves in veins?

  Yes, to prevent backflow of blood
• Are there valves in capillaries?

  No
• Lumen diameter in veins?

  Relatively large
• Lumen diameter in capillaries?

  Very small
• What is an artery?

  Blood vessel that carries blood under high-pressure away from the heart
• What is a vein?

  Blood vessel that carries blood back to the heart
• What is a capillary?

  A very thin blood vessel through which the exchange of materials between blood and cells take place