Nursing Elites

1. 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.

2. 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.

3. Homeostasis is the body's maintenance of a stable internal environment.

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

Correct answer: A

Rationale: Homeostasis refers to the body's ability to maintain a stable internal environment despite external changes. It involves processes that regulate various physiological factors such as temperature, pH, and blood sugar levels within a narrow range. This ensures that the body's cells can function optimally. Therefore, the correct answer is True. Choices B, C, and D are incorrect because homeostasis aims to maintain stability, not instability, in the internal environment.

4. Do chromosomes get longer as a cell ages?

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

Correct answer: B

Rationale: Chromosomes do not get longer as a cell ages. In fact, chromosomes condense and become more compact during cell division to ensure proper segregation. Choice A is incorrect because chromosomes do not elongate with age. Choice C is not the correct answer as there is scientific evidence to support that chromosomes do not lengthen over time. Choice D is not the right option as the correct answer is 'False' in this case.

5. Which part of the nephron is closest to the collecting duct?

• A. Distal convoluted tubule (DCT)
• B. Bowman's Capsule
• C. Afferent Arteriole
• D. Proximal Convoluted Tubule (PCT)

Correct answer: A

Rationale: The correct answer is the Distal convoluted tubule (DCT). The DCT is the part of the nephron closest to the collecting duct, where the final adjustments to electrolyte and fluid balance are made. Bowman's Capsule is located at the beginning of the nephron, where filtration of blood occurs. The Afferent Arteriole brings blood to the glomerulus for filtration. The Proximal Convoluted Tubule (PCT) is situated after the Bowman's Capsule and is not the part closest to the collecting duct.

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