Nursing Elites

1. Which structure serves as the normal pacemaker of the heart?

• A. SA node
• B. AV node
• C. Purkinje fibers
• D. Atria

Correct answer: A

Rationale: The correct answer is the SA node. The sinoatrial (SA) node is known as the natural pacemaker of the heart as it generates electrical impulses initiating each heartbeat. The SA node is located in the right atrium and sets the rhythm and rate of the heartbeat. The AV node (choice B) is responsible for delaying the electrical impulse to allow the atria to contract before the ventricles. Purkinje fibers (choice C) are specialized cardiac fibers responsible for the rapid conduction of impulses to the myocardial cells, and the atria (choice D) are the upper chambers of the heart involved in receiving blood from the veins.

2. 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?

• A. Stroke volume
• B. Cardiac output
• C. End-diastolic volume
• D. Ejection fraction

Correct answer: A

Rationale: The correct answer is A: Stroke volume. Stroke volume refers to the volume of blood ejected by the left ventricle during each heartbeat. This is determined by preload (the degree of stretch of the cardiac muscle fibers at the end of diastole), contractility (the force of myocardial contraction), and afterload (the pressure or resistance that the ventricle must overcome to eject blood). Choice B, Cardiac output, is the volume of blood pumped by the heart per minute and is calculated by multiplying the heart rate by the stroke volume. Choice C, End-diastolic volume, is the volume of blood in the ventricle at the end of diastole before contraction. Choice D, Ejection fraction, is the proportion of blood pumped out of the ventricle with each contraction, calculated by dividing the stroke volume by the end-diastolic volume.

3. This test measures the amount of blood the heart pumps with each beat, often used to assess heart function.

• A. Ejection fraction
• B. Cardiac output
• C. Stroke volume
• D. End-diastolic volume

Correct answer: A

Rationale: The correct answer is A: Ejection fraction. Ejection fraction is a measure of the percentage of blood that is pumped out of the left ventricle with each beat, used to assess heart function. Choice B, Cardiac output, is the total volume of blood pumped by the heart per minute and is not specific to each beat. Choice C, Stroke volume, is the amount of blood ejected by the heart in one contraction but does not specify the percentage of blood pumped out. Choice D, End-diastolic volume, is the volume of blood in the ventricle just before it contracts and does not directly measure the blood pumped with each beat.

4. What condition is characterized by the inflammation of the heart's outer lining, often causing chest pain and other symptoms?

• A. Pericarditis
• B. Endocarditis
• C. Myocarditis
• D. Valvular heart disease

Correct answer: A

Rationale: Pericarditis is the correct answer because it is the inflammation of the pericardium, the outer lining of the heart. This condition commonly presents with symptoms like chest pain. Endocarditis (choice B) is the inflammation of the inner lining of the heart chambers and valves. Myocarditis (choice C) is the inflammation of the heart muscle itself. Valvular heart disease (choice D) refers to various conditions affecting the heart valves, not specifically the outer lining of the heart.

5. What condition involves a weakened and bulging aorta, the main artery in the body, potentially leading to rupture?

• A. Aortic aneurysm
• B. Arterial stenosis
• C. Pulmonary embolism
• D. Deep vein thrombosis

Correct answer: A

Rationale: An aortic aneurysm is a condition characterized by the weakening and bulging of the aorta, the body's main artery. If left untreated, this bulging may lead to a rupture, causing severe complications. Arterial stenosis refers to the narrowing of an artery, not the weakening and bulging seen in an aortic aneurysm. Pulmonary embolism involves a blockage in the pulmonary artery, which is different from the weakening and bulging in an aortic aneurysm. Deep vein thrombosis is the formation of a blood clot in a deep vein, not related to the condition described in the question.

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