Nursing Elites

1. Ceroid pigments and lipofuscin accumulate with aging, impairing a cell's ability to withstand the damaging effects of oxygen free radicals.

• A. TRUE
• B. FALSE
• C. Not Sure
• D. None of the above

Correct answer: A

Rationale: The statement provided in the question is true. Ceroid pigments and lipofuscin are products of cellular damage and aging. These substances accumulate within cells over time and can impair cellular functions, including the ability to withstand the damaging effects of oxygen free radicals. Choice B, 'False,' is incorrect because the accumulation of ceroid pigments and lipofuscin does indeed impair a cell's ability to deal with oxidative stress. Choices C and D are also incorrect as the statement is true.

2. Which of the following cardiac valves prevents blood from returning to the left ventricle of the heart?

• A. pulmonic
• B. mitral
• C. tricuspid
• D. aortic

Correct answer: D

Rationale: The correct answer is the aortic valve. The aortic valve is located between the left ventricle and the aorta, preventing the backflow of blood into the left ventricle once it has been pumped out during systole. Choice A, pulmonic, is incorrect as it is associated with the right side of the heart. Choice B, mitral, is incorrect as it is the valve between the left atrium and ventricle. Choice C, tricuspid, is incorrect as it is located between the right atrium and ventricle.

3. Positive feedback mechanisms usually result in

• A. changes returning values away from a set point.
• B. stable conditions around a set point.
• C. unstable conditions.
• D. long-term changes.

Correct answer: C

Rationale: Positive feedback mechanisms usually result in unstable conditions. In a positive feedback loop, the output enhances or amplifies the changes that are occurring, leading to a deviation from the initial set point. Therefore, positive feedback does not bring values back towards the set point (Choice A). Choice B is incorrect because positive feedback does not promote stability around a set point. Choice D is also incorrect as positive feedback mechanisms typically do not lead to long-term changes; instead, they intensify the initial change, causing instability.

4. Metabolism refers to all of the chemical reactions in an organism that support life. Is this statement true?

• A. True
• B. False
• C. Not Sure
• D. None of the above

Correct answer: A

Rationale: The statement is true. Metabolism indeed refers to all of the chemical reactions in an organism that support life. It is essential for various processes in the body, including converting food into energy, building and repairing tissues, and eliminating waste products. Choice B is incorrect because metabolism does encompass all chemical reactions that sustain life. Choice C is incorrect as the definition of metabolism is clear. Choice D is incorrect as the statement provided is true.

5. What is the most useful application of ultrasonography for diagnostic examination?

• A. dense organs, such as bones.
• B. air-filled organs, such as lungs.
• C. soft internal structures, such as fetuses.
• D. microscopic structures.

Correct answer: C

Rationale: Ultrasonography is a medical imaging technique that uses sound waves to visualize internal body structures. It is particularly effective for examining soft tissues like organs, blood vessels, and fetuses. Choice A is incorrect because bones are better visualized using techniques like X-rays. Choice B is incorrect as air-filled organs like lungs are not well visualized with ultrasound due to air being a poor conductor of sound waves. Choice D is incorrect since ultrasonography cannot visualize structures at a microscopic level, as it is used for larger internal structures.

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