What causes heart disease and how can it be treated? Baseline (Flightpath D): To be able to state that the heartbeat is maintained by a group of cells that acts as a pacemaker and give some ways in which the heart can stop functioning efficiently. Describe why a person may need an artificial pacemaker or an artificial heart. Further (Flightpath C&B): to be able to explain why an irregular heartbeat is detrimental to health and describe why people may have objections to heart transplants. Summarise the advantages and disadvantages of different treatments for heart problems. Challenge Flightpath A): to be able to explain how a natural pacemaker maintains the heartbeat and suggest how an artificial pacemaker regulates an irregular heartbeat. Evaluate in detail the different methods used in the treatment of heart problems.

The heart rate of the average person is 70 beats per minute. calculate how many times the average human heartbeats in a year? 70 beats per minute 4200 beats per hour 100,800 beats per day 36,792,000 beats per year If you live to be 80 years old, your heart would have beaten approximately 2,943,360, 000 times

What could go wrong with this heart?

  Advantages Disadvantages artificial pacemakers biological valves artificial valves artificial hearts heart transplants

Exam question M1.(a) any two from: • carbon dioxide / CO2 • urea •        protein •        water / H2O •        hormones / insulin. ignore food / waste / alcohol / drugs / enzymes ignore glucose and oxygen allow two correct hormones for 2 marks allow two correct food components for 2 marks allow antibodies allow antitoxins 2 (b)     (i)      plasma 1 Platelets 1 (ii)     (cardiac) muscle allow muscular 1

6 mark question 0 marks - No relevant content Level 1 (1−2 marks) There is a description of at least one advantage of the cow tissue valve or a description of at least one disadvantage of the cow tissue valve. Level 2 (3−4 marks) There is a description of at least one advantage of the cow tissue valve and at least one disadvantage of the cow tissue valve. Level 3 (5−6 marks) There is a description of the advantages and disadvantages of the cow tissue valve a description of several advantages of the cow tissue valve and at least one disadvantage. Examples of the points made in the response Advantages of cow tissue valve: • abundant supply of cows • so shorter waiting time ignore can take many years to find a suitable human donor • no need for tissue typing • quicker operation • less invasive or shorter recovery time • cheaper operation costs • less operation / anaesthetic risks. Disadvantages of cow tissue valve: • made from cow so possible objections on religious grounds ignore ethical arguments • new procedure so could be unknown risks allow possible transfer of disease from cow • risks of using a stent eg. blood clots, stent breaking or valve tearing • not proven as a long term treatment • may be rejected ignore information copied directly from the table without value added.