Nursing Elites

1. 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.

2. 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.

3. Which of the following is a type of heart valve disease where the aortic valve becomes narrowed, restricting blood flow from the heart to the rest of the body?

• A. Aortic stenosis
• B. Mitral stenosis
• C. Tricuspid regurgitation
• D. Pulmonary hypertension

Correct answer: A

Rationale: The correct answer is Aortic stenosis. In aortic stenosis, the aortic valve becomes narrowed, which obstructs the blood flow from the heart to the rest of the body. This condition can lead to symptoms like chest pain, shortness of breath, and fainting. Mitral stenosis (choice B) involves narrowing of the mitral valve, not the aortic valve. Tricuspid regurgitation (choice C) is a condition where the tricuspid valve leaks, causing blood to flow backward in the heart. Pulmonary hypertension (choice D) is high blood pressure in the arteries of the lungs.

4. 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.

5. 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.

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