organisation

• which blood vessel carries blood from the heart to the lungs?

  pulmonary artery
• which blood vessel carries blood from the lungs to the heart?

  pulmonary vein
• explain how and why heart rate varies with exercise

  • it increases during exercise
  • more oxygen needs to be supplied to muscles
• from which chamber of the heart does blood flow into the pulmonary artery?

  right ventricle