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

Answer: Cardiac muscle is a specialized involuntary muscle tissue found 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 briefly describe their functions.

Answer: The four chambers are the right atrium, right ventricle, left atrium, and left ventricle. The right atrium receives deoxygenated blood from the body, the right ventricle pumps it to the lungs, the left atrium receives oxygenated blood from the lungs, and the left ventricle pumps oxygen-rich blood to the body.

Question 1: Calculate the cardiac output if the heart rate is 75 beats per minute and the stroke volume (amount of blood pumped per beat) is 70 mL. Use the formula: Cardiac Output = Heart Rate x Stroke Volume. Provide answer in liters per minute.

Answer: 5.25 liters per minute

Question 1: Describe a safe and ethical method to measure an individual's resting heart rate. Include necessary precautions.

Answer: To measure resting heart rate, the individual should sit quietly for at least 5 minutes, then place their index and middle fingers on the radial artery wrist. Count the number of beats in 60 seconds. Precautions include ensuring the person is relaxed, avoiding caffeine or vigorous activity beforehand, and washing hands before taking measurements.

Question 1: A study records the thickness of the ventricular walls in 50 individuals. The average thickness is 11 mm with a standard deviation of 2 mm. How would an abnormally thick wall (e.g., 15 mm) affect heart function? Explain your reasoning.

Answer: An abnormally thick ventricular wall, known as hypertrophy, can reduce the chamber's ability to fill properly and may impair the efficiency of blood pumping. This can lead to increased workload on the heart and potential heart failure.

Question 1: Explain the pathway of blood flow through the heart, including all chambers and valves involved.

Answer: Blood enters the right atrium from the vena cavae, then passes through the tricuspid valve into the right ventricle. From there, it is pumped through the pulmonary valve into the pulmonary arteries and to the lungs. Oxygenated blood returns via the pulmonary veins to the left atrium, passes through the bicuspid (mitral) valve into the left ventricle, and is then pumped through the aortic valve into the aorta to circulate throughout the body.

Question 1: Discuss how understanding heart anatomy has contributed to the development of artificial heart valves and their importance in modern medicine.

Answer: Knowledge of heart valve structure and function has enabled scientists to design artificial valves that can replace damaged ones, restoring normal blood flow and preventing heart failure. These innovations are crucial for patients with severe valve diseases.