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

Answer: Cardiac muscle is a specialized type of muscle tissue found only in the heart that enables the heart to contract and pump blood throughout the body.

Question 2: List the four main chambers of the human heart and state whether each is an atrium or a ventricle.

Answer: Right atrium, right ventricle, left atrium, left ventricle.

Question 3: Explain how the valves in the heart prevent the backflow of blood.

Answer: Heart valves act as one-way doors that open to allow blood to flow forward and close to prevent it from flowing backward.

Question 4: Calculate the amount of blood pumped by the heart in one minute if the cardiac output is 5 liters per minute and the heart beats 70 times per minute. (Use the formula: Cardiac output = Stroke volume × Heart rate)

Answer: Stroke volume = 5 liters / 70 beats = approximately 0.0714 liters per beat.

Question 5: Describe a simple experiment to measure your resting pulse rate and explain what variables need to be controlled.

Answer: To measure resting pulse rate, find your pulse at the wrist or neck, count the beats in 60 seconds, and record the number. Control variables include ensuring the person is at rest, seated comfortably, and has not recently exercised to get an accurate resting rate.

Question 6: In a scenario where blood flow is obstructed due to a clogged coronary artery, explain what part of the heart is most likely affected and why.

Answer: The part of the heart most likely affected is the myocardium (heart muscle) supplied by that coronary artery, because blockage reduces oxygen and nutrient supply, leading to tissue damage.

Question 7: Identify the main differences between arteries and veins in terms of structure and function.

Answer: Arteries carry oxygen-rich blood away from the heart and have thick, muscular walls; veins carry oxygen-poor blood toward the heart and have thinner walls with valves to prevent backflow.

Question 8: What is the significance of the coronary arteries in the circulatory system?

Answer: Coronary arteries supply oxygen-rich blood to the heart muscle itself, which is essential for its function and survival.

Question 9: Fill in the blank: The blood leaving the heart through the aorta flows to the _______.

Answer: body

Question 10: Describe how the structure of the heart allows it to contract rhythmically and efficiently to pump blood.

Answer: The heart's muscular walls, especially the myocardium, are specialized for contraction. The conduction system, including the sinoatrial node, coordinates rhythmic impulses, allowing the heart to contract in a synchronized and efficient manner.