Nokea
From where do these originate, behind the cusps of the aortic valve, in an area known as Valsalva's sinus?
- A. Pulmonary valve
- B. Aortic valve
- C. Tricuspid valve
- D. Mitral valve
Correct Answer: B
Rationale: Rationale: The correct answer is B - Aortic valve. This is because Valsalva's sinus is located behind the cusps of the aortic valve. The sinuses of Valsalva are pouch-like dilations found at the root of the aorta, just above the aortic valve. These sinuses are important in preventing backflow of blood into the heart during diastole. The other choices, A, C, and D, are incorrect because they do not originate from Valsalva's sinus. The pulmonary valve is located in the pulmonary artery, the tricuspid valve is between the right atrium and right ventricle, and the mitral valve is between the left atrium and left ventricle.
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To detect and treat the most common complication of MI, what should the nurse do?
- A. Measure hourly urine output
- B. Auscultate the chest for crackles
- C. Use continuous cardiac monitoring
- D. Take vital signs every 2 hours for the first 8 hours
Correct Answer: C
Rationale: Continuous monitoring detects dysrhythmias.
The client asks about side effects of taking digoxin. How does the nurse respond?
- A. Anorexia can be a side effect of digoxin.
- B. Tachycardia can be a side effect of digoxin.
- C. Constipation can be a side effect of digoxin.
- D. Urinary retention can be a side effect of digoxin.
Correct Answer: A
Rationale: The correct answer is A: Anorexia can be a side effect of digoxin. Digoxin is known to cause anorexia due to its impact on the gastrointestinal system. It can lead to nausea, vomiting, and loss of appetite, resulting in anorexia. Tachycardia (choice B) is not a common side effect of digoxin, as it is actually used to treat certain types of arrhythmias. Constipation (choice C) and urinary retention (choice D) are also not typically associated with digoxin use. In summary, anorexia is a known side effect of digoxin, while tachycardia, constipation, and urinary retention are not commonly linked to this medication.
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 impulse from the SA node is delayed at the AV node to allow time for the atria to contract before the ventricles. The AV node acts as a gatekeeper, slowing down the electrical signal before transmitting it to the Bundle of His, which then conducts the signal to the ventricles. This delay ensures proper coordination between atrial and ventricular contractions. Choices C and D are incorrect as the SA node does not delay its own impulse, and the aorta is not involved in the conduction system.
The nurse is administering enoxaparin (Lovenox) to a client. What is the most important lab value to monitor?
- A. Platelet count
- B. Hemoglobin
- C. White blood cell count
- D. aPTT
Correct Answer: A
Rationale: The correct answer is A: Platelet count. Enoxaparin is an anticoagulant that works by preventing blood clots. Monitoring platelet count is crucial to assess for potential thrombocytopenia, a side effect of enoxaparin that can increase the risk of bleeding. Hemoglobin (B) and White blood cell count (C) are not directly affected by enoxaparin. aPTT (D) is not the most important lab value to monitor as enoxaparin does not directly affect this clotting parameter.
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: The correct answer is A: Refractoriness. Refractoriness refers to the period during which cardiac cells are unable to respond to a new stimulus while still contracting from a previous stimulus. This is essential for preventing premature re-stimulation and ensuring proper cardiac function.
B: Excitability refers to the ability of cardiac cells to respond to a stimulus, which is the opposite of what is described in the question.
C: Contractility is the ability of cardiac cells to contract in response to an electrical stimulus, not related to the inability to respond to a new stimulus during contraction.
D: Automaticity is the ability of cardiac cells to spontaneously generate electrical impulses, unrelated to the inability to respond to a new stimulus during contraction.