Circulatory system

• What are the two main functions of the circulatory system?

  Transport and protection against disease
• What is the role of red blood cells?

  • Transport oxygen
  • Contain haemoglobin rich in iron
  • Biconcave shape for large surface area
  • Absence of nucleus to carry more haemoglobin
• What is the function of white blood cells?

  • Defence against disease
  • Lymphocytes produce antibodies
  • Phagocytes engulf and digest microorganisms
• What is the main function of plasma in blood?

  Transport of blood cells and nutrients
• What role do platelets play in blood clotting?

  Convert fibrinogen to fibrin to form clots
• What happens to red blood cells in water?

  They burst due to osmosis
• What are the three types of blood vessels and their directions of blood flow?

  • Arteries: Carry blood away from the heart
  • Veins: Carry blood back to the heart
  • Capillaries: from arteries to veins
• What is the direction of blood flow in arteries?

  Away from the heart
• Why do arteries have thick walls?

  To withstand high blood pressure
• What is the lumen diameter of veins compared to arteries?

  Veins have a larger lumen
• What is the role of valves in veins?

  Prevent backflow of blood
• What is the thickness of capillary walls?

  One cell thick
• What is the function of the heart?

  Pumps blood around the body
• What is double circulation in the heart?

  • Blood travels through the heart twice
  • First to the lungs for oxygenation
  • Then to the rest of the body
• Which heart chamber has the thickest walls?

  The left ventricle
• What is the role of coronary blood vessels?

  Supply blood to the heart muscle
• What are the benefits of regular exercise on the circulatory system?

  • Strengthens the heart muscle
  • Increases cardiac output
  • Improves overall cardiovascular health
• What is cardiac output?

  Volume of blood pumped per minute
• How are heart rate and pulse rate related?

  They are the same measurement
• What is the recovery time after exercise?

  • Time for pulse rate to return to normal
  • Indicates cardiovascular fitness
• Capillary

  A very thin blood vessels through which the exchange of material between blood and cells take place