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. Which fibers distribute the electrical impulse to the ventricles, causing them to contract?

• A. Purkinje fibers
• B. SA node
• C. AV node
• D. Bundle of His

Correct answer: A

Rationale: The correct answer is Purkinje fibers. Purkinje fibers are specialized conducting fibers that distribute the electrical impulse to the ventricles, leading to their contraction. The SA node (sinoatrial node) is responsible for initiating the electrical impulse in the heart, the AV node (atrioventricular node) delays the impulse to allow for proper atrial contraction before ventricular contraction, and the Bundle of His transmits the impulse from the AV node to the ventricles. Therefore, choices B, C, and D are not the correct options for fibers directly distributing the impulse to the ventricles.

3. Which valve prevents backflow of blood into the right ventricle from the pulmonary artery?

• A. Pulmonary valve
• B. Aortic valve
• C. Tricuspid valve
• D. Mitral valve

Correct answer: A

Rationale: The correct answer is the Pulmonary valve. The Pulmonary valve prevents backflow of blood into the right ventricle from the pulmonary artery after it has been ejected. The Aortic valve (choice B) prevents backflow from the aorta into the left ventricle. The Tricuspid valve (choice C) prevents backflow of blood into the right atrium from the right ventricle. The Mitral valve (choice D) prevents backflow from the left ventricle into the left atrium.

4. What is a condition where the heart is unable to relax properly between beats, reducing its ability to fill with blood?

• A. Diastolic heart failure
• B. Systolic heart failure
• C. Hypertrophic cardiomyopathy
• D. Restrictive cardiomyopathy

Correct answer: A

Rationale: The correct answer is A: Diastolic heart failure. In diastolic heart failure, the heart is unable to relax properly between beats, leading to a reduced ability to fill with blood. This condition primarily affects the heart's filling function rather than its pumping function, which is characteristic of systolic heart failure (choice B). Hypertrophic cardiomyopathy (choice C) involves the abnormal thickening of the heart muscle, while restrictive cardiomyopathy (choice D) is characterized by the heart muscle becoming stiff and less compliant. Therefore, choices B, C, and D are incorrect in the context of a heart condition where relaxation between beats is impaired.

5. When administering furosemide (Lasix) to a client, which lab value is most important to monitor?

• A. Potassium
• B. Sodium
• C. Calcium
• D. Chloride

Correct answer: A

Rationale: When administering furosemide (Lasix), it is crucial to monitor potassium levels closely. Furosemide is a loop diuretic that can lead to potassium loss, potentially causing hypokalemia. Monitoring potassium levels helps prevent adverse effects associated with low potassium, such as cardiac arrhythmias. While monitoring sodium, calcium, and chloride levels may also be important in certain situations, potassium is the most critical to monitor when administering furosemide.

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