Circulatory System of a Mammal

• What are the two key features of a mammal's circulatory system?

  • It is a closed system.
  • It is a double circulatory system.
• What does a closed system mean?

  The blood remains within the blood vessels.
• What does a double circulatory system mean?

  The blood passes through the heart twice each circuit.
• Why do mammals need a double circulatory system?

  • To manage the pressure of blood flow.
  • The pressure is low in the lungs, but must be higher in the rest of the body.
• Why is blood pressure low in the lungs?

  • To prevent damage to the capillaries.
  • To slow down blood flow, allowing more time for gas exchange.
• Why must blood pressure be high in the rest of the body?

  To ensure that blood reaches all the respiring cells in the body.
• What blood vessels supply the cardiac muscle with oxygen?

  Coronary arteries
• What key vessels are attached to the heart?

  • Vena cava
  • Aorta
  • Pulmonary vein
  • Pulmonary artery
• What key blood vessels are attached to the lungs?

  • Pulmonary vein
  • Pulmonary artery
• What key blood vessels are attached to the kidneys?

  • Renal vein
  • Renal artery
• How are major blood vessels connected?

  They are connected via arteries, arterioles, capillaries and veins.
• The mammal circulatory system

  A) Pulmonary vein

  B) Renal artery

  C) Vena cava