Question 1: Define the term 'cardiac muscle' and explain its role in the heart.

Answer: Cardiac muscle is a specialised type of involuntary muscle tissue found only in the heart, responsible for contracting to pump blood throughout the body.

Question 2: Describe the pathway of blood through the four chambers of the heart.

Answer: Blood enters the right atrium from the body, moves to the right ventricle, is pumped to the lungs for oxygenation, returns to the left atrium, moves into the left ventricle, and is then pumped out to the body.

Question 1: Calculate the cardiac output when the heart rate is 72 beats per minute and the stroke volume is 70 millilitres. (Use the formula: Cardiac output = Heart rate × Stroke volume).

Answer: 5.04 litres per minute

Question 2: If a person’s stroke volume increases to 80 millilitres while their heart rate remains at 72 beats per minute, what is their new cardiac output?

Answer: 5.76 litres per minute

Question 1: Outline the steps involved in measuring a person's pulse rate accurately.

Answer: Find a pulse point (e.g., wrist or neck), use fingertips to feel the pulse, count the number of beats in 60 seconds or 30 seconds and multiply by two if counting for 30 seconds, and record the pulse rate in beats per minute. Ensure fingers do not press too hard and the person is at rest.

Question 2: Identify two safety precautions to observe during a practical experiment involving the heart or circulatory system.

Answer: Ensure the use of sterile equipment to prevent infection, and avoid applying excessive pressure that could cause injury or inaccurate readings.

Question 1: A patient has a resting heart rate of 60 beats per minute and a stroke volume of 75 millilitres. Calculate their cardiac output and explain what this indicates about their heart function.

Answer: Using the formula: Cardiac output = Heart rate × Stroke volume, the cardiac output is 60 × 75 ml = 4500 ml or 4.5 litres per minute. This relatively low but normal resting cardiac output suggests a healthy heart functioning efficiently at rest.

Question 1: Explain how an increase in physical activity affects stroke volume and cardiac output. (6 marks)

Answer: During physical activity, the muscles require more oxygen and nutrients. To meet this demand, stroke volume increases due to stronger and more forceful heart contractions, and the heart rate also increases. Together, these changes elevate cardiac output, enabling more blood to circulate rapidly, thus supplying the muscles with the necessary oxygen and removing waste products efficiently.

Question 2: Identify a technological advancement used in medicine to assess heart health and briefly describe its purpose.

Answer: Electrocardiograms (ECGs) are used to measure the electrical activity of the heart, helping diagnose arrhythmias, heart attacks, and other cardiac conditions.