Circulatory system

• What protein do red blood cells contain that is essential for oxygen transport?

  Haemoglobin
• What shape are red blood cells?

  Biconcave
• What element is found in haemoglobin?

  Iron
• Why do red blood cells not have a nucleus?

  To maximize space for haemoglobin
• What is the primary function of red blood cells?

  Transport oxygen
• What is the role of white blood cells?

  Defend against disease
• What do phagocytes do?

  Engulf and digest microbes
• What is the process called when phagocytes engulf microbes?

  Phagocytosis
• What is the function of lymphocytes?

  Produce antibodies
• What do platelets do?

  Cause blood clotting
• How do platelets contribute to scab formation?

  By converting fibrinogen to fibrin
• What does plasma transport?

  Cells, glucose, amino acids, CO₂, hormones, and urea
• What happens to red blood cells when placed in water?

  They swell and burst due to osmosis
• Why do red blood cells burst in water?

  They have no cell wall
• What are the characteristics of arteries, veins, and capillaries?

  • Arteries:
  • Direction: Away from heart
  • Thickness: Thick
  • Pressure: High
  • Valves: None
  • Veins:
  • Direction: Back to heart
  • Thickness: Relatively thin
  • Pressure: Low
  • Valves: Yes
  • Capillaries:
  • Direction: From arteries to veins
  • Thickness: 1 cell thick
  • Pressure: Low
  • Valves: None
• What is the function of the pulmonary vein?

  Transports oxygenated blood from lungs to heart
• What does the aorta do?

  Transports oxygenated blood from heart to body
• What is the role of the vena cava?

  Transports deoxygenated blood from body to heart
• What does the pulmonary artery do?

  Transports deoxygenated blood from heart to lungs
• What is the function of the hepatic artery?

  Transports oxygen and glucose to the liver
• What does the hepatic portal vein carry?

  Digested food from small intestine to liver
• What does the hepatic vein transport?

  Glucose and amino acids from liver to heart and lungs
• What does the renal artery do?

  Transports urea to kidneys for excretion
• What does the renal vein carry?

  Blood low in urea from kidney to vena cava and CO₂ to heart and lungs
• What is double circulation?

  • Blood travels through the heart twice:

  1. From heart to lungs (pulmonary circulation)
  2. From heart to body (systemic circulation)
• What is cardiac output?

  How much blood is pumped out per minute
• What is recovery rate in relation to exercise?

  The time taken for pulse to return to normal after exercise
• How does exercise affect the heart muscle?

  It strengthens the heart muscle and increases cardiac output
• Why does heart rate rise during exercise?

  To pump more blood to muscles for glucose and oxygen
• What is the purpose of increased cardiac output during exercise?

  To supply more glucose and oxygen to muscles
• How does exercise affect blood pressure?

  It increases blood pressure to bring more blood flow to muscles