Nursing Elites

1. After the AV node, the electrical impulse is then transmitted into the _________, and into the _________.

• A. Purkinje fibers, ventricles
• B. Atria, ventricles
• C. Bundle of His, Purkinje fibers
• D. Ventricles, Purkinje fibers

Correct answer: C

Rationale: The correct answer is C. After the AV node, the electrical impulse is transmitted to the Bundle of His and then to the Purkinje fibers. This sequence is crucial for the coordinated contraction of the ventricles. Choice A (Purkinje fibers, ventricles) is incorrect because the Purkinje fibers come after the Bundle of His in the sequence of electrical conduction. Choice B (Atria, ventricles) is incorrect because the impulse does not go back to the atria after passing through the AV node. Choice D (Ventricles, Purkinje fibers) is incorrect because the impulse first reaches the Bundle of His before spreading to the Purkinje fibers.

2. Which neurotransmitter is released by the sympathetic nervous system (SNS) to increase heart rate and the force of contraction of the heart?

• A. Norepinephrine
• B. Epinephrine
• C. Dopamine
• D. Acetylcholine

Correct answer: A

Rationale: The correct answer is Norepinephrine. Norepinephrine is the neurotransmitter released by the sympathetic nervous system that increases heart rate and the force of contraction. Epinephrine, though similar, is more involved in the fight-or-flight response and has a broader range of effects on various organs. Dopamine is not primarily responsible for increasing heart rate and contractility. Acetylcholine is a neurotransmitter that predominantly acts on the parasympathetic nervous system to decrease heart rate and contractility.

3. What structure separates the left and right sides of the heart?

• A. Interventricular septum
• B. Endocardium
• C. Epicardium
• D. Pericardium

Correct answer: A

Rationale: The interventricular septum is the correct answer as it is the wall that separates the left and right sides of the heart, ensuring the oxygenated and deoxygenated blood do not mix. The endocardium is the inner lining of the heart chambers, the epicardium is the outermost layer of the heart wall, and the pericardium is the sac that surrounds the heart, providing protection and anchoring the heart in place. Therefore, choices B, C, and D are incorrect in the context of separating the left and right sides of the heart.

4. Which neurotransmitter released by the parasympathetic nervous system can decrease heart rate?

• A. Acetylcholine
• B. Norepinephrine
• C. Dopamine
• D. Serotonin

Correct answer: A

Rationale: Acetylcholine is the correct answer. It is a neurotransmitter released by the parasympathetic nervous system that can decrease heart rate. Norepinephrine, dopamine, and serotonin are neurotransmitters that usually have different effects on the body and are not specifically associated with decreasing heart rate. Norepinephrine, for example, is often related to the fight-or-flight response and can increase heart rate.

5. Which test measures how well the lungs work by assessing the amount of air the lungs can hold and how quickly air can be exhaled?

• A. Spirometry
• B. Pulse oximetry
• C. Arterial blood gas (ABG)
• D. Chest X-ray

Correct answer: A

Rationale: The correct answer is A, Spirometry. Spirometry is a pulmonary function test that evaluates lung function by measuring the amount of air a person can exhale and how quickly, assisting in the diagnosis of conditions such as asthma and COPD. Choices B, C, and D are incorrect because Pulse oximetry measures oxygen saturation in the blood, Arterial blood gas (ABG) evaluates blood pH, oxygen, and carbon dioxide levels, and a Chest X-ray provides an image of the lungs but does not measure lung function.

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