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. When administering dobutamine to a client, what is the most important parameter to assess?

• A. Blood pressure
• B. Heart rate
• C. Oxygen saturation
• D. Respiratory rate

Correct answer: A

Rationale: When giving dobutamine, the most critical parameter to assess is blood pressure. Dobutamine is known to cause significant changes in blood pressure, making it essential to closely monitor this parameter to prevent adverse effects. While heart rate is also important to monitor, blood pressure takes precedence due to the potential for hemodynamic instability caused by dobutamine. Oxygen saturation and respiratory rate, although vital signs to monitor, are not typically affected directly by dobutamine administration.

3. Which condition involves the heart muscle becoming abnormally thickened, reducing its ability to pump blood?

• A. Hypertrophic cardiomyopathy
• B. Dilated cardiomyopathy
• C. Restrictive cardiomyopathy
• D. Ischemic cardiomyopathy

Correct answer: A

Rationale: The correct answer is A: Hypertrophic cardiomyopathy. In this condition, the heart muscle thickens, leading to a decreased ability to pump blood effectively. Choice B, Dilated cardiomyopathy, is characterized by the heart chambers enlarging and weakening. Choice C, Restrictive cardiomyopathy, involves the heart muscle becoming rigid and less compliant. Choice D, Ischemic cardiomyopathy, is when the heart muscle is weakened due to reduced blood flow.

4. Which valves close during ventricular systole and open during ventricular diastole?

• A. Semilunar valves
• B. Atrioventricular Valves
• C. Mitral valve
• D. Tricuspid valve

Correct answer: B

Rationale: The correct answer is B: Atrioventricular Valves. The atrioventricular (AV) valves, including the mitral valve and tricuspid valve, close during ventricular systole to prevent backflow of blood from the ventricles into the atria. They open during ventricular diastole to allow blood flow from the atria into the ventricles. Semilunar valves, choice A, are located at the exits of the ventricles and prevent backflow into the ventricles. The mitral valve and tricuspid valve, choices C and D, are specific types of AV valves.

5. 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.

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