blood vessels

• What flows round the body in the circulatory system?

  Blood
• What do arteries do?

  They carry oxygenated blood away from the heart
• What is the color of oxygenated blood in arteries?

  Bright-red
• How do arteries respond to blood flow?

  They stretch and return to shape
• What are the walls of arteries made of?

  Muscle and elastic fibers
• What do veins do?

  Carry deoxygenated blood from the organs to the heart
• What is the color of blood in veins?

  Deep purple-red
• Do veins have a pulse?

  No, they do not have a pulse
• How do the walls of veins compare to arteries?

  Veins have thinner walls than arteries
• What prevents backflow of blood in veins?

  Valves in the veins
• How do valves in veins function?

  They open and close with blood flow
• What forms a network linking arteries and veins?

  Capillaries
• What is the structure of capillaries?

  Narrow with very thin walls
• What substances diffuse from blood into cells?

  Oxygen and glucose
• What do cells produce that passes into the blood?

  Carbon dioxide
• What are the three main types of blood vessels and their functions?

  • Arteries: Carry blood away from the heart
  • Veins: Carry blood towards the heart
  • Capillaries: Link arteries and veins, facilitate diffusion
• What are the key differences between arteries and veins?

  • Arteries: Thick walls, pulse, oxygenated blood
  • Veins: Thinner walls, no pulse, deoxygenated blood
• What are the roles of capillaries in the circulatory system?

  • Form a network linking arteries and veins
  • Allow diffusion of oxygen and glucose into cells
  • Facilitate the passage of carbon dioxide into blood