Question 1: Define Adrenaline and describe its primary role in the body.

Answer: Adrenaline is a hormone produced by the adrenal glands that prepares the body for 'fight or flight' responses by increasing heart rate, blood flow, and energy supply.

Question 2: Explain how Thyroxine influences the body's metabolic rate.

Answer: Thyroxine increases the metabolic rate by stimulating enzyme activity, leading to higher energy consumption and heat production.

Question 3: Describe the mechanism by which Adrenaline is released into the bloodstream.

Answer: Adrenaline is released when the nervous system signals the adrenal glands in response to stress or danger, leading to hormone secretion into the blood.

Question 1: If a person's blood adrenaline level rises from 0.2 ng/mL to 1.0 ng/mL during stress, by what factor has the adrenaline concentration increased?

Answer: 5

Question 2: A Thyroxine injection increases the basal metabolic rate (BMR) by 15%. If the original BMR is 1500 kcal/day, what is the new BMR after injection?

Answer: 1725 kcal/day

Question 1: Describe a safe way to collect blood samples for measuring hormone levels in a laboratory setting.

Answer: Use sterile equipment, wear gloves, follow proper disposal procedures, and ensure the patient is comfortable and informed.

Question 2: Identify two variables that should be controlled during an experiment measuring the effect of stress on adrenaline levels.

Answer: Variables include the time of day and the physical activity level of subjects.

Question 1: A group of students undergoes a stress test. Their blood adrenaline levels are measured before and after. Before: 0.3 ng/mL, after: 0.9 ng/mL. Explain what this data suggests about adrenaline's role during stress.

Answer: The data indicates that adrenaline levels increase significantly during stress, supporting its role in preparing the body for 'fight or flight' responses by increasing alertness and energy availability.

Question 1: Discuss how Adrenaline and Thyroxine work together to prepare the body for physical activity. Include their effects and mechanisms. (6 marks)

Answer: Adrenaline and Thyroxine both increase energy availability during physical activity. Adrenaline rapidly prepares the body for immediate response by increasing heart rate, blood flow, and glucose release, while Thyroxine sustains increased metabolic activity over time by elevating the basal metabolic rate, ensuring continuous energy supply.

Question 1: Explain how understanding how Adrenaline works can help in developing better treatments for allergic reactions.

Answer: Understanding Adrenaline's role allows for the development of emergency treatments like adrenaline auto-injectors to quickly counteract severe allergic reactions by relaxing airway muscles and increasing blood pressure.