Nursing Elites

1. What test measures the electrical activity of the heart over a 24- or 48-hour period?

• A. Holter monitor
• B. Electrocardiogram
• C. Stress test
• D. Chest X-ray

Correct answer: A

Rationale: The correct answer is A, Holter monitor. A Holter monitor is a portable device that continuously records the heart's electrical activity over 24 to 48 hours, aiding in the diagnosis of arrhythmias and other heart conditions. Choice B, an Electrocardiogram, provides a snapshot of the heart's electrical activity at a specific point in time, not over an extended period like a Holter monitor. Choice C, a Stress test, measures how the heart responds to physical activity and is not used for continuous monitoring of electrical activity. Choice D, a Chest X-ray, is used to visualize the structures of the chest, not to measure the heart's electrical activity.

2. What is the amount of blood the heart pumps through the circulatory system in a minute?

• A. Cardiac output
• B. Stroke volume
• C. End-diastolic volume
• D. Ejection fraction

Correct answer: A

Rationale: The correct answer is A: Cardiac output. Cardiac output is the volume of blood pumped by the heart per minute. It is calculated by multiplying the stroke volume (the amount of blood pumped out of the heart in each beat) by the heart rate (number of heartbeats per minute). This question specifically asks for the total amount of blood pumped through the circulatory system in a minute, which is represented by cardiac output. Choices B, C, and D are incorrect because stroke volume refers to the amount of blood pumped out of the heart in each beat, end-diastolic volume is the volume of blood in the heart at the end of diastole, and ejection fraction is the percentage of blood pumped out of the heart with each contraction, not the total amount pumped per minute.

3. This test measures the amount of blood the heart pumps with each beat, often used to assess heart function.

• A. Ejection fraction
• B. Cardiac output
• C. Stroke volume
• D. End-diastolic volume

Correct answer: A

Rationale: The correct answer is A: Ejection fraction. Ejection fraction is a measure of the percentage of blood that is pumped out of the left ventricle with each beat, used to assess heart function. Choice B, Cardiac output, is the total volume of blood pumped by the heart per minute and is not specific to each beat. Choice C, Stroke volume, is the amount of blood ejected by the heart in one contraction but does not specify the percentage of blood pumped out. Choice D, End-diastolic volume, is the volume of blood in the ventricle just before it contracts and does not directly measure the blood pumped with each beat.

4. Which of the following is a central vasoconstrictor and peripheral vasodilator?

• A. Parasympathetic nervous system
• B. Sympathetic nervous system
• C. Dopamine
• D. Epinephrine

Correct answer: D

Rationale: The correct answer is D, Epinephrine. Epinephrine acts as a central vasoconstrictor and peripheral vasodilator. It increases heart rate and blood flow to muscles, helping to prepare the body for a 'fight or flight' response. Parasympathetic nervous system (choice A) does not cause vasoconstriction but rather vasodilation. The sympathetic nervous system (choice B) is primarily responsible for the fight or flight response, causing vasoconstriction. Dopamine (choice C) primarily acts as a neurotransmitter and hormone, not directly causing central vasoconstriction and peripheral vasodilation.

5. 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.

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