Cardiovascular System Practice Exam

Correct Answer: A

Rationale: The correct answer is A: Coronary perfusion pressure. Coronary perfusion pressure refers to the process of coronary artery blood flow to the myocardium during diastole when coronary vascular resistance is reduced. This process ensures that the myocardium receives sufficient oxygen and nutrients for proper functioning. Choice B, Coronary vascular resistance, is the opposite of what is described in the question. During coronary perfusion, resistance is reduced to enhance blood flow. Choices C and D, Diastolic filling and Ventricular ejection, do not directly relate to the process of coronary artery blood flow during diastole.

Correct Answer: A

Rationale: Pneumothorax is the correct answer. It is the collapse of a lung due to air leaking into the space between the lung and chest wall. This condition often requires emergency treatment. Choice B, Pleural effusion, is the buildup of excess fluid between the layers of the pleura outside the lung, not air. Choice C, Pulmonary fibrosis, is a lung disease characterized by scarring and thickening of lung tissue, not related to lung collapse. Choice D, Lung cancer, is the uncontrolled growth of abnormal cells in the lung, not directly causing lung collapse.

Correct Answer: A

Rationale: The correct answer is A: Preload. Preload is the degree of myocardial fiber stretch before contraction, influenced by the volume of blood returning to the heart. This parameter is related to the amount of blood in the ventricles at the end of diastole. Choice B, Afterload, refers to the pressure or resistance that the ventricles must overcome to eject blood. Choice C, Contractility, is the intrinsic ability of the heart muscle to contract. Choice D, Ejection fraction, is the percentage of blood pumped out of the ventricles with each contraction.

Correct Answer: A

Rationale: The correct answer is to avoid foods high in potassium. Spironolactone is a potassium-sparing diuretic, meaning it helps the body retain potassium and can lead to hyperkalemia if too much potassium is consumed. Choices B, C, and D are incorrect because increasing intake of potassium-rich foods can worsen hyperkalemia, while avoiding foods high in sodium is not the primary concern when taking spironolactone.

Correct Answer: B

Rationale: The correct answer is B: Pulmonary valve. The pulmonary valve opens during ventricular systole to allow blood to flow from the right ventricle into the pulmonary artery. The aortic valve opens during ventricular systole to allow blood to flow from the left ventricle into the aorta. The mitral valve and tricuspid valve are atrioventricular valves that open during ventricular diastole to allow blood to flow from the atria into the ventricles.