Nursing Elites

1. What is the ability of cardiac cells to respond to an impulse by contracting?

• A. Excitability
• B. Contractility
• C. Rhythmicity
• D. Conductivity

Correct answer: A

Rationale: Excitability is the correct term that describes the ability of cardiac cells to respond to an impulse by contracting. Excitability refers to the cell's ability to respond to stimuli and generate an action potential. Choice B, Contractility, is incorrect as it refers to the ability of cardiac cells to contract after receiving a stimulus, not the response to the impulse itself. Choice C, Rhythmicity, is incorrect as it pertains to the heart's ability to contract rhythmically without external stimulation. Choice D, Conductivity, is incorrect as it refers to the ability of cardiac cells to transmit an impulse from cell to cell, not the direct response to the impulse by contracting.

2. What structures hold up the AV valves and are anchored to the ventricular wall by the papillary muscles?

• A. Chordae tendineae
• B. Papillary muscles
• C. Semilunar valves
• D. Aortic valve

Correct answer: A

Rationale: The correct answer is A: Chordae tendineae. Chordae tendineae are fibrous cords that connect the AV valves to the papillary muscles, preventing the valves from inverting during ventricular contraction. Papillary muscles (choice B) anchor the chordae tendineae to the ventricular wall but do not hold up the AV valves directly. Semilunar valves (choice C) are located between the ventricles and the major arteries and are not involved in holding up the AV valves. The aortic valve (choice D) is one of the semilunar valves and is not responsible for holding up the AV valves.

3. Which surgical procedure involves grafting a blood vessel to bypass a blocked artery in the heart?

• A. Coronary artery bypass graft (CABG)
• B. Valve replacement
• C. Stent placement
• D. Angioplasty

Correct answer: A

Rationale: The correct answer is A, Coronary artery bypass graft (CABG). This surgical procedure involves grafting a blood vessel to bypass a blocked coronary artery, improving blood flow to the heart muscle. Choice B, Valve replacement, is a procedure to replace a damaged heart valve and is not directly related to bypassing blocked arteries. Choice C, Stent placement, involves inserting a mesh tube to keep blocked arteries open and is different from grafting a blood vessel. Choice D, Angioplasty, is a procedure to widen narrowed or blocked arteries, typically using a balloon catheter, and does not involve grafting a blood vessel.

4. In cases of myocardial infarction leading to shock, which medication is appropriate to counteract shock?

• A. Atropine
• B. Dopamine
• C. Digoxin
• D. Adenosine

Correct answer: B

Rationale: In cases of myocardial infarction leading to shock, dopamine is the drug of choice. Dopamine helps increase blood pressure and improve blood flow to vital organs, making it beneficial in managing shock. Atropine is mainly used for symptomatic bradycardia, not for shock. Digoxin is a cardiac glycoside used in heart failure and atrial fibrillation, not for managing shock. Adenosine is typically used for diagnosing and treating supraventricular tachycardias, not for shock associated with myocardial infarction.

5. What is the ability of cardiac cells to generate an electrical impulse without being stimulated by an external source?

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

Correct answer: A

Rationale: Automaticity is the correct answer because it refers to the inherent ability of cardiac cells to generate electrical impulses without the need for external stimulation. Contractility (Choice B) is the ability of the heart muscle to contract and generate force, not related to electrical impulse generation. Conductivity (Choice C) refers to the ability of cardiac cells to transmit electrical impulses from cell to cell, not the spontaneous generation of impulses. Refractoriness (Choice D) is the period during which the cardiac cells are recovering and not able to respond to a new stimulus, not the spontaneous generation of impulses.

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