Nursing Elites

1. During a healthy heartbeat, the P wave on an ECG represents

• A. The repolarization of the ventricles.
• B. The electrical conduction through the AV node.
• C. The contraction phase of the ventricles (systole)
• D. The depolarization of the atria.

Correct answer: D

Rationale: The correct answer is D: The P wave on an ECG represents the depolarization of the atria. During a healthy heartbeat, the P wave is the first positive deflection seen on the ECG and reflects the initiation of the electrical impulse in the atria, leading to atrial contraction. It is followed by the QRS complex, which represents the depolarization of the ventricles. Options A, B, and C are incorrect because the P wave specifically corresponds to atrial depolarization, not repolarization of the ventricles, electrical conduction through the AV node, or ventricular contraction. Understanding the sequence of electrical events in the heart as represented on an ECG is crucial for interpreting cardiac function and identifying potential abnormalities.

2. What are the two main types of nuclear decay, and what differentiates them?

• A. Fission and fusion, based on the size of the nucleus
• B. Alpha and beta decay, based on the emitted particle.
• C. Spontaneous and induced decay, based on the trigger.
• D. Isotope decay and chain reactions, based on the stability of the nucleus.

Correct answer: B

Rationale: The two main types of nuclear decay are alpha and beta decay, based on the emitted particle. In alpha decay, an alpha particle (which consists of two protons and two neutrons) is emitted from the nucleus. In beta decay, a beta particle (either an electron or a positron) is emitted from the nucleus. These types of decay are differentiated by the particles they emit, rather than the size of the nucleus, trigger, or stability of the nucleus.

3. A guitar string vibrates at a fundamental frequency of 440 Hz. What is the frequency of the second harmonic (first overtone)?

• A. 220 Hz
• B. 440 Hz
• C. 880 Hz
• D. 1760 Hz

Correct answer: C

Rationale: Harmonics have frequencies that are multiples of the fundamental frequency. The second harmonic has a frequency twice the fundamental, so it's 440 Hz * 2 = 880 Hz.

4. Which element is used in fluorescent lamps and emits ultraviolet light when excited?

• A. Mercury
• B. Neon
• C. Argon
• D. Krypton

Correct answer: A

Rationale: Mercury vapor in fluorescent lamps generates UV light that excites phosphors on the lamp's inner surface, producing visible light.

5. Electroencephalography (EEG) measures electrical activity in the brain, primarily reflecting the activity of:

• A. Neurons
• B. Astrocytes
• C. Oligodendrocytes
• D. Microglia

Correct answer: A

Rationale: The correct answer is A: Neurons. Electroencephalography (EEG) measures the electrical activity in the brain, which is primarily generated by the neurons. Neurons are the main cells responsible for transmitting electrical signals in the brain, making them the key source of the brain's electrical activity. Astrocytes, oligodendrocytes, and microglia are important supporting cells in the brain but do not generate the electrical impulses that EEG measures. Therefore, the correct choice is A: Neurons.

6. Which of the following is an example of a commensal relationship between a microorganism and a human?

• A. Salmonella causing food poisoning
• B. taphylococcus aureus causing skin infections
• C. coli living in the gut
• D. Rabies virus causing neurological disease

Correct answer: C

Rationale: Rationale: A commensal relationship is a type of symbiotic relationship in which one organism benefits, while the other is neither harmed nor benefited. In this case, E. coli living in the gut is an example of a commensal relationship because it can benefit from the environment in the gut without causing harm to the human host. Option A, Salmonella causing food poisoning, is an example of a pathogenic relationship where the microorganism causes harm to the host. Option B, Staphylococcus aureus causing skin infections, is also an example of a pathogenic relationship where the microorganism causes harm to the host. Option D, Rabies virus causing neurological disease, is another example of a pathogenic relationship where the microorganism causes harm to the host.

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