VEINS

• DESCRIBE MUSCLE LAYER OF VEINS?

  relatively thin
• WHY ARE VEIN MUSCLE LAYERS RELATIVELY THIN?

  cannot control blood flow
• DESCRIBE ELASTIC LAYER OF VEINS?

  relatively thin
• WHY ARE THE ELASTIC LAYERS OF VEINS RELATIVELY THIN?

  pressure is much lower
• DESCRIBE THE WALL THICKNESS OF VEINS?

  thin
• WHY ARE VEIN WALLS THIN?

  • lower pressure (less risk of bursting)
  • also allows for them to easily flatten, helping the flow of blood to the heart
• DO VEINS HAVE VALVES?

  yes