Nokea
What is the approximate stroke volume of the heart?
- A. Approximately 60 mL of blood per beat
- B. Approximately 70 mL of blood per beat
- C. Approximately 80 mL of blood per beat
- D. Approximately 90 mL of blood per beat
Correct Answer: B
Rationale: The correct answer is B (Approximately 70 mL of blood per beat). The average human stroke volume is around 70 mL. This volume represents the amount of blood ejected by the left ventricle in each contraction. It is important to note that stroke volume can vary depending on factors such as age, fitness level, and cardiac health. Choices A, C, and D are incorrect because they do not align with the typical range of stroke volume in a healthy adult. Option A (60 mL) is slightly below the average, while options C (80 mL) and D (90 mL) are above the typical range. Therefore, the best approximation for stroke volume in the heart is around 70 mL per beat.
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A patient uses a mixed β-adrenergic blocking drug for treatment of migraine headaches. What effect might this drug have on BP and why?
- A. Decreased BP due to reduced cardiac output
- B. Increased BP due to unopposed α-adrenergic activity
- C. No effect on BP
- D. Decreased BP due to vasodilation
Correct Answer: A
Rationale: β-blockers reduce heart rate and contractility, lowering BP.
What is a condition where the lung's alveoli are permanently enlarged and damaged, leading to shortness of breath?
- A. Emphysema
- B. Bronchitis
- C. Atelectasis
- D. Pulmonary fibrosis
Correct Answer: A
Rationale: The correct answer is A: Emphysema. Emphysema is a condition where the lung's alveoli are permanently enlarged and damaged, causing shortness of breath. This occurs due to the destruction of the alveoli walls, leading to decreased surface area for oxygen exchange. This results in difficulty breathing and reduced oxygen supply to the body. Bronchitis (B) is inflammation of the bronchial tubes, not alveoli damage. Atelectasis (C) is the collapse of lung tissue, not enlargement. Pulmonary fibrosis (D) is scarring of lung tissue, not alveoli enlargement.
What is a condition characterized by the presence of air or gas in the pleural space, leading to the collapse of the lung?
- A. Pneumothorax
- B. Pulmonary embolism
- C. Pleural effusion
- D. Atelectasis
Correct Answer: A
Rationale: The correct answer is A: Pneumothorax. Pneumothorax is the presence of air or gas in the pleural space, causing the lung to collapse. This occurs when air enters the pleural space due to trauma or a lung condition. Pulmonary embolism (B) is a blockage of the artery in the lung by a blood clot. Pleural effusion (C) is the accumulation of fluid in the pleural space. Atelectasis (D) is the collapse of a part of or entire lung due to blockage or pressure. Therefore, the correct answer is A as it specifically describes the condition of air in the pleural space causing lung collapse.
What is the condition where a blood clot blocks an artery in the lungs, causing shortness of breath, chest pain, and other symptoms?
- A. Pulmonary embolism
- B. Pneumothorax
- C. Pleural effusion
- D. Aneurysm
Correct Answer: A
Rationale: The correct answer is A: Pulmonary embolism. A pulmonary embolism occurs when a blood clot travels to the lungs and blocks an artery, leading to symptoms like shortness of breath and chest pain. This happens because the clot obstructs blood flow to the lung tissue, causing a decrease in oxygen levels. The other choices, B: Pneumothorax, C: Pleural effusion, and D: Aneurysm, do not involve a blood clot blocking an artery in the lungs. Pneumothorax is a collapsed lung due to air in the chest cavity, Pleural effusion is the accumulation of fluid in the space between the lungs and chest wall, and an Aneurysm is a bulging and weakened blood vessel.
What accurately describes the pathophysiology of CAD?
- A. Partial or total occlusion of the coronary artery occurs during the stage of raised fibrous plaque
- B. Endothelial alteration may be caused by chemical irritants such as hyperlipidemia or by tobacco use
- C. Collateral circulation in the coronary circulation is more likely to be present in the young patient with CAD
- D. The leading theory of atherogenesis proposes that infection and fatty dietary intake are the basic underlying causes of atherosclerosis
Correct Answer: B
Rationale: Endothelial damage initiates plaque formation.