Question 1: Define the term 'artery' and explain its primary function in the circulatory system.

Answer: An artery is a blood vessel that carries oxygenated blood away from the heart to the body tissues. Its primary function is to withstand high pressure and ensure efficient blood flow.

Question 2: Describe the structural differences between arteries and veins that allow them to perform their functions effectively.

Answer: Arteries have thick, muscular, and elastic walls to cope with high pressure, while veins have thinner walls and valves to prevent backflow as blood returns to the heart at lower pressure.

Question 3: Explain how capillaries facilitate the exchange of substances between blood and body cells.

Answer: Capillaries have very thin walls, only one cell thick, which allows nutrients, oxygen, and waste products to diffuse efficiently between the blood and surrounding tissues.

Question 1: Calculate the blood flow rate if a blood vessel has a cross-sectional area of 0.0005 m^2 and the blood velocity is 0.3 m/s. Use the formula: Flow Rate = Cross-sectional Area × Velocity. Show your working.

Answer: Flow Rate = 0.0005 m^2 × 0.3 m/s = 0.00015 m^3/s

Question 2: A patient's systolic blood pressure is recorded as 120 mmHg. Convert this pressure into pascals (Pa). (1 mmHg = 133.3 Pa)

Answer: 120 mmHg × 133.3 Pa/mmHg = 15996 Pa

Question 1: Design a simple experiment to investigate how exercise affects blood pressure. Include the independent and dependent variables, and mention any safety precautions.

Answer: The experiment involves measuring the blood pressure of participants before and after exercise. The independent variable is the level of exercise (e.g., rest vs. running), and the dependent variable is blood pressure. Safety precautions include ensuring participants are healthy, monitoring exertion levels, and providing hydration and rest after exercise.

Question 1: A study records blood flow rates in arteries of 1.2 × 10^-4 m^3/s, veins of 8.0 × 10^-5 m^3/s, and capillaries of 2.5 × 10^-8 m^3/s. Explain why blood flow is slowest in capillaries despite their large total surface area.

Answer: Blood flow is slowest in capillaries because their small diameter and large total surface area create greater resistance to flow, allowing efficient exchange of substances despite the slower movement.

Question 1: Explain the importance of valves in veins and how they contribute to the efficiency of blood return to the heart, especially from the lower limbs.

Answer: Valves in veins prevent backflow of blood and ensure unidirectional flow towards the heart. They are especially important in the lower limbs, where gravity opposes blood flow, by opening when blood moves upward and closing to stop it from flowing back down.

Question 2: Multiple Choice: Which type of blood vessel has the thickest muscular wall to handle high pressure?

Answer: Artery

Question 1: Describe how the development of artificial blood vessels or stents can help in treating cardiovascular diseases. Include potential benefits and challenges.

Answer: Artificial blood vessels and stents can restore blood flow in blocked or damaged vessels, reducing risks of heart attacks and strokes. Benefits include improved patient outcomes and reduced need for major surgery. Challenges involve ensuring biocompatibility, preventing rejection or clotting, and maintaining long-term functionality.