1. 1
   A cyclist wears a heart-rate monitor during a race. Her resting heart rate is controlled by a small group of cells that generate the electrical impulses which set the timing of each heartbeat. During the race, her doctor also explains how blood is pumped around her body.

   (a)

   Where in the heart are these cells located?

   [1 mark]

   • ARight atrium
   • BLeft ventricle
   • CAorta
   • DPulmonary vein

   (b)

   The doctor explains that blood returning from the body enters the right side of the cyclist's heart before being sent to the lungs. Which chamber of the heart pumps this blood to the lungs for gas exchange?

   [1 mark]

   • ALeft atrium
   • BLeft ventricle
   • CRight ventricle
   • DRight atrium

   (c)

   Explain why the human circulatory system is described as a 'double circulatory system'.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   A hospital laboratory analyses a patient's blood sample and separates it into its different components before recording the results in the patient's notes.

   (a)

   Which component of blood is responsible for causing blood to clot at the site of a wound?

   [1 mark]

   • AWhite blood cells
   • BPlasma
   • CRed blood cells
   • DPlatelets

   (b)

   The laboratory notes state that the patient has a high count of the blood component that helps fight infection by producing antibodies and engulfing pathogens. Which component of blood is this?

   [1 mark]

   • APlasma
   • BWhite blood cells
   • CPlatelets
   • DRed blood cells

   (c)

   Describe how red blood cells are adapted to carry out their function of transporting oxygen.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   A patient is diagnosed with a faulty heart valve that has developed a leak, and the cardiologist also examines the patient's veins and capillaries as part of a general assessment of the circulatory system.

   (a)

   The cardiologist also examines the patient's arteries. Describe how the structure of an artery relates to its function of carrying blood away from the heart at high pressure.

   [3 marks]

   (b)

   Describe how the structures of veins and capillaries each relate to their functions.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   A public health study reports that rates of coronary heart disease have fallen in a population after a national campaign encouraged wider use of statins and increased access to stent surgery. Doctors in the study also compare stents and statins with more invasive treatments, such as valve replacement and heart transplants, for patients with advanced cardiovascular disease.

   (a)

   Explain how coronary heart disease develops, and explain how stents and statins each help to treat or reduce the risk of the disease.

   [6 marks]

   (b)

   For patients with advanced cardiovascular disease, doctors in the study also considered biological or mechanical heart valve replacement, and heart transplants, as alternatives to drug treatment or stents. Evaluate the advantages and disadvantages of treating cardiovascular disease using drugs, mechanical devices, or transplants.

   [6 marks]

   Total for question 4: 12 marks

End of questions