Nursing Elites

1. Where is the impulse from the SA node delayed, enabling atrial contraction to complete before the ventricles are stimulated and contract?

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

Correct answer: A

Rationale: The correct answer is AV node. The AV node is responsible for delaying the impulse from the SA node, allowing the atria to contract before the ventricles. This delay ensures the effective pumping of blood in a coordinated manner. Choices B, C, and D are incorrect because the Bundle of His is responsible for transmitting the impulse to the Purkinje fibers, the SA node is the pacemaker of the heart responsible for initiating the heartbeat, and the aorta is the main artery carrying oxygenated blood from the heart to the body, respectively, none of which are involved in delaying the impulse to allow atrial contraction before ventricular contraction.

2. Which heart chamber ejects blood into the systemic arterial circulation via the aorta?

• A. Right atrium
• B. Left atrium
• C. Right ventricle
• D. Left ventricle

Correct answer: D

Rationale: The correct answer is D, Left ventricle. The left ventricle pumps oxygenated blood into the systemic circulation via the aorta. This chamber receives oxygen-rich blood from the left atrium and contracts forcefully to propel blood into the aorta, distributing it to the body. The other options, right atrium, left atrium, and right ventricle, do not directly eject blood into the systemic arterial circulation via the aorta. The right atrium receives deoxygenated blood from the body, the left atrium receives oxygenated blood from the lungs, and the right ventricle pumps blood to the lungs for oxygenation.

3. What is the term that describes the inability of cardiac cells to respond to a new stimulus while they are still in contraction from a previous stimulus?

• A. Refractoriness
• B. Excitability
• C. Contractility
• D. Automaticity

Correct answer: A

Rationale: Refractoriness is the correct term to describe the inability of cardiac cells to respond to a new stimulus while they are still in contraction from a previous stimulus. This period is essential for the heart to complete its contraction and relaxation phases without interference. Excitability refers to the ability of cells to respond to stimuli, not the inability to respond. Contractility is the force of cardiac muscle contraction, and automaticity is the ability of cardiac cells to generate electrical impulses spontaneously, which are not relevant to the described scenario.

4. The nurse is caring for a client on digoxin. What is the most important assessment before administering this medication?

• A. Check the client’s heart rate.
• B. Check the client’s blood pressure.
• C. Check the client’s respiratory rate.
• D. Check the client’s oxygen saturation.

Correct answer: A

Rationale: The correct answer is to check the client’s heart rate before administering digoxin because one of the side effects of digoxin is bradycardia. Monitoring the heart rate is crucial to assess whether the client's heart rate is within the acceptable range before giving the medication. Checking the blood pressure (Choice B), respiratory rate (Choice C), or oxygen saturation (Choice D) are important assessments in general patient care, but they are not specifically related to the administration of digoxin.

5. What is the amount of tension the ventricle must develop during contraction to eject blood from the left ventricle into the aorta?

• A. Afterload
• B. Preload
• C. Automaticity
• D. Ejection fraction

Correct answer: A

Rationale: Afterload is the correct answer because it refers to the pressure or tension that the ventricle must overcome during systole to eject blood into the aorta. Preload, on the other hand, is the degree of stretch of the ventricular muscle at the end of diastole before it contracts. Automaticity is the ability of the heart to generate electrical impulses independently, and ejection fraction is the percentage of blood pumped out of the ventricle with each heartbeat. Therefore, in the context of the question, afterload best describes the amount of tension the ventricle must develop to eject blood into the aorta.

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