Question 1: Explain in your own words what dialysis is and why it is necessary for individuals with kidney failure.

Answer: Dialysis is a medical process that artificially removes waste products, excess salts, and fluids from the blood when the kidneys can no longer perform these functions naturally. It is necessary to maintain the body's internal balance, or homeostasis, in individuals with kidney failure.

Question 1: Define 'ultrafiltration' in the context of dialysis.

Answer: Ultrafiltration is the process of removing excess water from the blood by applying pressure across a semi-permeable membrane during dialysis.

Question 2: Describe how a dialysis machine mimics the function of the kidneys.

Answer: A dialysis machine uses a semi-permeable membrane and a controlled flow of dialysis fluid to allow waste products, excess salts, and water to diffuse from the blood into the dialysis fluid, effectively performing the filtration and excretion functions of healthy kidneys.

Question 1: A dialysis machine removes 200 mL of waste solution over a 4-hour session. Calculate the rate of waste removal in mL per hour.

Answer: Rate = Total volume removed / Time = 200 mL / 4 hours = 50 mL/hour

Question 2: If a patient's blood volume is 5 litres and the dialysis removes 1 litre of excess fluid during treatment, what percentage of their blood volume has been cleared of excess fluid?

Answer: Percentage = (Volume removed / Blood volume) × 100 = (1 L / 5 L) × 100 = 20%

Question 1: Design a simple experimental setup to test the effectiveness of different semi-permeable membranes used in dialysis. Identify the independent, dependent, and control variables.

Answer: The setup would include a container with a semi-permeable membrane, a solution with known concentrations of waste products, and a method to measure waste removal. Independent variable: type of membrane; Dependent variable: amount of waste removed; Control variables: volume of solution, temperature, flow rate.

Question 2: List three safety precautions engineers should consider when designing a dialysis machine.

Answer: Ensuring sterile conditions to prevent infection, controlling pressure to avoid membrane rupture, and monitoring blood flow rates to prevent damage to blood cells.

Question 1: A study reports that a new dialysis membrane reduces waste removal time by 25% compared to current models. Discuss how this improvement could impact patient care and the engineering considerations involved.

Answer: Reducing waste removal time can improve patient comfort, reduce treatment duration, and increase machine throughput. Engineering considerations include membrane material durability, biocompatibility, flow rates, and ensuring the membrane's selectivity to waste products.

Question 2: In industry, synthetic membranes are used in water purification. Explain how principles of dialysis are applied in this technology.

Answer: Both processes use semi-permeable membranes to allow selective diffusion of contaminants. In water purification, membranes remove impurities like salts and pollutants from water, similar to how dialysis removes waste from blood.