Nursing Elites

1. Which of the following structures is responsible for transmitting electrical impulses in the nervous system?

• A. Neuron
• B. Axon
• C. Myelin
• D. Dendrite

Correct answer: A

Rationale: The correct answer is A: Neuron. Neurons are specialized cells that transmit electrical impulses in the nervous system. While the axon is the part responsible for conducting these impulses over long distances, it is the neuron as a whole that is ultimately responsible for transmitting electrical impulses. Myelin is a fatty substance that surrounds and insulates axons, speeding up signal transmission. Dendrites, on the other hand, receive signals from other neurons. Therefore, although the axon plays a significant role in transmission, the neuron is the fundamental unit responsible for transmitting electrical impulses in the nervous system.

2. When a certain plant is introduced into an area, and the population of a certain insect species declines, what can be concluded from this?

• A. The plant is toxic to the insect in question.
• B. The plant competes with and drives out plants that the insect feeds on.
• C. The insect population was declining anyway; the fact that it happened when the plant was introduced is a coincidence.
• D. All of these explanations may be possible; further investigation is necessary to determine which is true.

Correct answer: D

Rationale: The given scenario presents multiple possible explanations for the decline in the insect population with the introduction of a particular plant. It could be due to the plant being toxic to the insect (Option A), competing with and driving out plants that the insect feeds on (Option B), or the decline could be coincidental with the plant introduction as the insect population was already decreasing (Option C). Without further investigation and evidence, it is not possible to definitively determine which explanation is correct. Therefore, all of these possibilities may be true, and thorough investigation is necessary to reach a conclusive conclusion.

3. Following successful heart transplant surgery, the patient's body will need to take medications to:

• A. Suppress the immune system and prevent rejection of the new heart.
• B. Reduce overall blood pressure.
• C. Dissolve any remaining blood clots.
• D. Stimulate the growth of new heart tissue.

Correct answer: A

Rationale: After heart transplant surgery, the patient's body will need to take medications to suppress the immune system and prevent rejection of the new heart. This is essential to ensure that the body does not identify the transplanted heart as a foreign entity and mount an immune response against it, which could lead to transplant rejection and failure. Choices B, C, and D are incorrect because post-heart transplant medications primarily focus on preventing rejection by suppressing the immune system, rather than reducing blood pressure, dissolving blood clots, or stimulating the growth of new heart tissue.

4. What is the relationship between the wavelength (λ) and frequency (f) of a wave with a constant speed (v)?

• A. λ = v / f
• B. λ = f / v
• C. λ = vf
• D. λ is independent of f and v

Correct answer: A

Rationale: The relationship between wavelength (λ), frequency (f), and speed (v) of a wave is given by the formula λ = v / f. This formula is derived from the wave equation v = fλ, where v is the speed of the wave, f is the frequency, and λ is the wavelength. By rearranging the equation, we get λ = v / f, indicating that the wavelength is inversely proportional to the frequency when the speed of the wave is constant. Therefore, choice A, λ = v / f, correctly represents the relationship between wavelength and frequency when the speed of the wave is held constant. Choice B, λ = f / v, is incorrect because it represents an inverse relationship between wavelength and speed, which is not the case. Choice C, λ = vf, is incorrect as it implies a direct relationship between wavelength, frequency, and speed, which is not accurate. Choice D, λ is independent of f and v, is incorrect as both frequency and speed affect the wavelength of a wave, as shown by the correct formula λ = v / f.

5. What is the primary function of lymph nodes, small, bean-shaped structures found along lymphatic vessels?

• A. To store excess lymph fluid
• B. To produce red blood cells
• C. To filter lymph and fight infection
• D. To transport lymph to the heart

Correct answer: C

Rationale: Lymph nodes primarily function to filter lymph and fight infection. They contain immune cells that help to remove pathogens and foreign particles from the lymph fluid as it passes through the nodes. This process helps to activate the immune response and defend the body against infections. Choice A is incorrect as lymph nodes do not store excess lymph fluid; they filter lymph. Choice B is incorrect as the production of red blood cells primarily occurs in the bone marrow, not in lymph nodes. Choice D is incorrect as lymph nodes do not transport lymph to the heart; they filter and process lymph to remove impurities and activate the immune response.

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