Nursing Elites

1. Which valve opens during ventricular systole and closes during ventricular diastole?

• A. Aortic valve
• B. Pulmonary valve
• C. Mitral valve
• D. Tricuspid valve

Correct answer: B

Rationale: The correct answer is B: Pulmonary valve. The pulmonary valve opens during ventricular systole to allow blood to flow from the right ventricle into the pulmonary artery. The aortic valve opens during ventricular systole to allow blood to flow from the left ventricle into the aorta. The mitral valve and tricuspid valve are atrioventricular valves that open during ventricular diastole to allow blood to flow from the atria into the ventricles.

2. This is a more accurate indicator of tissue perfusion. It represents the cardiac output in terms of liters per minute per square meter of body surface area. Its normal range is 2.4-4 L/min.

• A. Cardiac Index
• B. Stroke volume
• C. Ejection fraction
• D. Cardiac output

Correct answer: A

Rationale: The correct answer is A: Cardiac Index. Cardiac Index is a measure of cardiac output relative to body surface area, providing a more accurate assessment of tissue perfusion. It is calculated by dividing the cardiac output by the body surface area. The normal range for cardiac index is 2.4-4 L/min/m². Choice B, Stroke volume, refers to the amount of blood ejected by the heart in one contraction and is not adjusted for body surface area. Choice C, Ejection fraction, is the percentage of blood pumped out of the heart's ventricles with each contraction, not adjusted for body surface area. Choice D, Cardiac output, is the total volume of blood pumped by the heart per minute, without considering body surface area.

3. Which term conceptualizes that the greater the myocardial fiber stretch, within physiologic limits, the more forceful the ventricular contraction, thereby increasing stroke volume?

• A. Frank-Starling’s Law
• B. Automaticity
• C. Contractility
• D. Excitability

Correct answer: A

Rationale: The correct answer is A, Frank-Starling’s Law. This law explains that within physiologic limits, the greater the stretch of myocardial fibers, the more forceful the ventricular contraction, leading to an increased stroke volume. Choice B, Automaticity, refers to the ability of cardiac cells to spontaneously generate electrical impulses. Choice C, Contractility, represents the intrinsic ability of the heart muscle to contract. Choice D, Excitability, refers to the ability of cardiac cells to respond to electrical stimuli.

4. Which fibers distribute the electrical impulse to the ventricles, causing them to contract?

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

Correct answer: A

Rationale: The correct answer is Purkinje fibers. Purkinje fibers are specialized conducting fibers that distribute the electrical impulse to the ventricles, leading to their contraction. The SA node (sinoatrial node) is responsible for initiating the electrical impulse in the heart, the AV node (atrioventricular node) delays the impulse to allow for proper atrial contraction before ventricular contraction, and the Bundle of His transmits the impulse from the AV node to the ventricles. Therefore, choices B, C, and D are not the correct options for fibers directly distributing the impulse to the ventricles.

5. What test measures the electrical activity of the heart and can detect heart rhythm problems?

• A. Electrocardiogram (ECG or EKG)
• B. Chest X-ray
• C. MRI
• D. CT scan

Correct answer: A

Rationale: The correct answer is Electrocardiogram (ECG or EKG). An electrocardiogram is a test that measures the electrical activity of the heart and can detect irregularities in heart rhythm. Choices B, C, and D are incorrect because a chest X-ray, MRI, and CT scan do not specifically measure the electrical activity of the heart or detect heart rhythm problems.

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