What is the term for the amount of blood ejected by the left ventricle into the aorta per beat, determined by preload, contractility, and afterload?

Correct Answer: A

Rationale: The correct answer is A: Stroke volume. Stroke volume is the amount of blood ejected by the left ventricle into the aorta per beat. Preload (end-diastolic volume), contractility, and afterload influence stroke volume. Cardiac output (B) is the total volume of blood pumped by the heart per minute. End-diastolic volume (C) is the volume of blood in the ventricle before contraction. Ejection fraction (D) is the percentage of blood ejected from the ventricle during systole.

Correct Answer: A

Rationale: The correct answer is A: Cardiac Index. Cardiac Index is a more accurate indicator of tissue perfusion as it takes into account the individual's body surface area, providing a more standardized measure. It is calculated by dividing the cardiac output by body surface area. This normalization allows for a more precise assessment of tissue perfusion compared to just cardiac output alone. The normal range of Cardiac Index is 2.4-4 L/min/m^2. Summary: - Choice B (Stroke volume) is incorrect because it is the volume of blood pumped out by the heart with each heartbeat, not accounting for body surface area. - Choice C (Ejection fraction) is incorrect because it is the percentage of blood ejected from the heart's left ventricle with each heartbeat, not adjusted for body surface area. - Choice D (Cardiac output) is incorrect because it doesn't consider the individual's body surface area, making it less accurate in assessing tissue perfusion.

Correct Answer: A

Rationale: The correct answer is A: Aortic valve. The aortic valve is located between the left ventricle and the aorta, preventing the backflow of blood into the left ventricle during diastole. This is essential for maintaining proper blood flow direction and preventing regurgitation. The other choices, B: Mitral valve, C: Tricuspid valve, and D: Pulmonary valve, are all located in different areas of the heart and serve different functions. The mitral valve is between the left atrium and ventricle, the tricuspid valve is between the right atrium and ventricle, and the pulmonary valve is between the right ventricle and pulmonary artery. None of these valves are responsible for preventing backflow into the left ventricle from the aorta.

Correct Answer: A

Rationale: The correct answer is A: Heart failure. This condition occurs when the heart is unable to pump enough blood to meet the body's needs. It can result from various factors such as high blood pressure, heart muscle damage, or heart valve disorders. In contrast, B (Myocardial infarction) refers to a heart attack caused by a blockage in the coronary arteries, C (Cardiomyopathy) is a disease of the heart muscle, and D (Pericarditis) is inflammation of the pericardium surrounding the heart. These conditions may affect the heart's function but do not specifically indicate the inability to pump sufficient blood like heart failure does.

Correct Answer: A

Rationale: The correct answer is A: Deep vein thrombosis (DVT). DVT is a blood clot that forms in a deep vein, commonly in the legs. It can lead to serious complications if the clot dislodges and travels to the lungs, causing a pulmonary embolism. Varicose veins (C) are enlarged, twisted veins near the surface of the skin, not involving deep veins. Atherosclerosis (D) is the build-up of plaque in arteries, not related to vein clot formation. Pulmonary embolism (B) is a complication of DVT, not the initial clot formation in a vein.