Nursing Elites

1. Which statement best conveys an aspect of the role of cerebrospinal fluid (CSF)?

• A. CSF provides immune protection to the brain and spinal cord by serving as a physical barrier.
• B. CSF cushions the brain and spinal cord, protecting them from injury.
• C. CSF plays a limited role in the exchange of nutrients and waste products between the blood and brain.
• D. CSF functions primarily as a medium for the transmission of nerve impulses.

Correct answer: B

Rationale: The correct answer is B. Cerebrospinal fluid primarily cushions the brain and spinal cord, protecting them from injury. Choice A is incorrect because while CSF contributes to the brain's immune environment, its main role is not providing immune protection as a physical barrier. Choice C is incorrect because CSF has a significant role in the exchange of nutrients and waste products, rather than a limited one. Choice D is incorrect as CSF is not primarily a medium for nerve impulse transmission, but rather serves as a protective and supportive fluid.

2. A male patient is being treated with sildenafil (Viagra) for erectile dysfunction. What condition would contraindicate the use of this medication?

• A. Peptic ulcer disease
• B. History of myocardial infarction
• C. Recent use of antihypertensive medications
• D. Use of nitrates

Correct answer: D

Rationale: The correct answer is D: Use of nitrates. Sildenafil (Viagra) is contraindicated in patients taking nitrates due to the risk of severe hypotension. Nitrates and sildenafil both cause vasodilation, and the combination can lead to a dangerous drop in blood pressure. Choice A, peptic ulcer disease, is not a contraindication for sildenafil use. Choice B, a history of myocardial infarction, is not a contraindication unless the patient is also taking nitrates. Choice C, recent use of antihypertensive medications, is not a contraindication but requires caution as the combination can lead to additive effects lowering blood pressure.

3. Which of the following describes the pathophysiology of exercise-induced asthma?

• A. Bronchospasm after exercise
• B. IgE-mediated inflammatory response to antigen
• C. Bronchoconstriction after ingesting high-allergen foods
• D. Increased mucus production due to a genetic mutation

Correct answer: A

Rationale: The correct answer is A: 'Bronchospasm after exercise.' Exercise-induced asthma involves the narrowing of the airways (bronchospasm) triggered by physical activity. This bronchospasm leads to symptoms such as coughing, wheezing, and shortness of breath. Choices B, C, and D are incorrect because exercise-induced asthma is not primarily caused by an IgE-mediated inflammatory response to an antigen, bronchoconstriction after ingesting high-allergen foods, or increased mucus production due to a genetic mutation.

4. What is responsible for initiating clonal selection?

• A. B cells
• B. T cells
• C. Antigens
• D. Lymphocytes

Correct answer: C

Rationale: Antigens are the correct answer as they are the molecules that trigger the immune response by binding to specific B or T cells. This binding activates these cells, leading to their proliferation and differentiation to fight off the antigen. B cells and T cells are the responders to antigens, not the initiators of clonal selection. Lymphocytes is a broad term encompassing both B and T cells, so it is not the specific factor responsible for initiating clonal selection.

5. What is the action of amphotericin B?

• A. It binds to ergosterol and forms holes in the membrane.
• B. It binds to an enzyme required for the synthesis of ergosterol.
• C. It disrupts the fungal cell walls rather than the cell membrane.
• D. It inhibits glucan synthetase required for glucan synthesis.

Correct answer: A

Rationale: Amphotericin B is an antifungal medication that acts by binding to ergosterol, a component of fungal cell membranes, forming pores that disrupt the integrity of the membrane. This action leads to leakage of cellular contents and ultimately cell death. Choice B is incorrect as amphotericin B does not bind to an enzyme required for the synthesis of ergosterol. Choice C is incorrect as the drug primarily affects the cell membrane rather than the cell wall. Choice D is also incorrect as amphotericin B does not inhibit glucan synthetase.

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