Question 1: Define Coronary Heart Disease and explain how it affects the heart's function.

Answer: Coronary Heart Disease is a condition characterised by the narrowing or blockage of the coronary arteries, which supply blood to the heart muscle. This reduces oxygen delivery, leading to chest pain, heart attacks, or other complications.

Question 2: Describe the main cause of atherosclerosis that leads to Coronary Heart Disease.

Answer: Atherosclerosis is primarily caused by the build-up of fatty deposits, such as cholesterol and other substances, along the arterial walls, leading to narrowing and hardening of the arteries.

Question 1: Calculate the percentage reduction in blood flow if a coronary artery narrows by 50% due to atherosclerosis. Use the formula: Percent reduction = [(Original flow - Reduced flow) / Original flow] × 100%. Assume initial blood flow is 100 units.

Answer: 50%

Question 2: A patient’s cholesterol level is measured at 6 mmol/L. If the recommended maximum is 5 mmol/L, by what percentage does the patient’s cholesterol exceed the recommended level?

Answer: 20%

Question 1: Describe a basic experimental setup to investigate the effect of saturated fat intake on blood cholesterol levels in humans. Mention the variables involved and safety considerations.

Answer: An experiment could involve two groups of volunteers, one consuming a diet high in saturated fats and the other a low-fat diet over several weeks. Variables include diet type (independent), blood cholesterol levels (dependent), and age, gender as controlled variables. Safety precautions include screening for allergies, monitoring health status, and obtaining informed consent to minimise health risks.

Question 1: A study reports that individuals with a BMI over 30 have a 2.5 times higher risk of developing Coronary Heart Disease compared to those with a BMI under 25. Explain what this data suggests about the relationship between BMI and heart disease risk.

Answer: The data suggests a strong correlation between high BMI (obesity) and increased risk of Coronary Heart Disease, indicating that excess body weight is a significant risk factor for developing the condition.

Question 2: In a population survey, 40% of individuals with high blood pressure also have high cholesterol levels. What does this co-occurrence imply about these risk factors?

Answer: This co-occurrence implies that high blood pressure and high cholesterol often occur together, and they may synergistically increase the risk of developing Coronary Heart Disease.

Question 1: Explain the process by which atherosclerosis can lead to a heart attack. Include the roles of cholesterol, plaque formation, and blood flow obstruction.

Answer: Atherosclerosis involves the build-up of fatty deposits, mainly cholesterol, within the arterial walls forming plaques. Over time, these plaques can rupture, causing blood clots to form. These clots can completely block coronary arteries, leading to a lack of oxygen supply to the heart muscle, which results in a heart attack.

Question 1: Describe how advancements in medical technology, such as stent placement, have improved the treatment of Coronary Heart Disease.

Answer: Stent placement involves inserting a tiny mesh tube into a narrowed coronary artery to keep it open, restoring blood flow. This minimally invasive procedure reduces the risk of heart attacks, shortens recovery times, and improves long-term outcomes for patients.

Question 2: Explain how public health policies aimed at reducing cholesterol levels could impact the prevalence of Coronary Heart Disease in the population.

Answer: Public health policies that promote healthy diets, physical activity, and regular screening can lower average cholesterol levels in the population. This reduces the incidence of atherosclerosis and related conditions, ultimately decreasing the prevalence and mortality rates of Coronary Heart Disease.