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: unstable conditions.

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. Which of the following is the measurement of the percentage of red blood cells in whole blood?

• A. Hematocrit
• B. Hemoglobin
• C. Mean corpuscular volume
• D. Reticulocyte count

Correct answer: Hematocrit

Rationale: The correct answer is 'Hematocrit.' Hematocrit is the measurement of the percentage of red blood cells in whole blood. It is used to diagnose conditions such as anemia and dehydration. Choice B, 'Hemoglobin,' measures the amount of hemoglobin in the blood, not the percentage of red blood cells. Choice C, 'Mean corpuscular volume,' measures the average volume of a red blood cell, not the percentage of red blood cells. Choice D, 'Reticulocyte count,' measures the percentage of young red blood cells in the blood, not the percentage of red blood cells.

3. Which of the following illustrates a positive feedback mechanism?

• A. Maintaining blood pressure
• B. Uterine contractions during childbirth
• C. Body temperature control
• D. Control of blood sugar

Correct answer: Uterine contractions during childbirth

Rationale: The correct answer is uterine contractions during childbirth. This is an example of a positive feedback mechanism where the initial stimulus (contractions) leads to an increase in intensity and frequency, ultimately resulting in childbirth. In contrast, choices A, C, and D (maintaining blood pressure, body temperature control, and control of blood sugar) are examples of negative feedback mechanisms. These mechanisms work to maintain stability by counteracting any deviations from the set point, rather than amplifying the response like in a positive feedback mechanism.

4. Is the following statement true: The anatomical position is lying down, as a cadaver would be positioned?

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

Correct answer: False

Rationale: The correct answer is False. The anatomical position is a standardized way of describing the human body's orientation in a consistent manner. The anatomical position is standing upright, facing forward, with the arms at the sides and palms facing forward. This position serves as a reference point for anatomical descriptions and directional terms. Therefore, the statement that the anatomical position is lying down, as a cadaver would be positioned, is incorrect. Choice A is incorrect because the anatomical position is not lying down. Choices C and D are also incorrect as there is a definitive answer to the question.

5. The recent discovery of taste receptors that detect sweetness in the small intestine illustrates that

• A. chemical responses occur in various parts of the body.
• B. new discoveries about anatomy and physiology are still being made.
• C. everything about anatomy and physiology has been discovered.
• D. the molecular and cellular level is crucial in anatomy and physiology.

Correct answer: new discoveries about anatomy and physiology are still being made.

Rationale: The recent discovery of taste receptors in the small intestine illustrates that new discoveries about anatomy and physiology are still being made. This finding demonstrates that our understanding of the human body is continuously evolving. Choice A is incorrect because the discovery does not imply that chemical responses occur in only one part of the body but rather showcases a specific new discovery. Choice C is incorrect as it is highly improbable that everything about anatomy and physiology has been discovered given the complexity of the human body. Choice D is incorrect as while the molecular and cellular level is important in anatomy and physiology, the primary focus of this discovery is on the new findings about the taste receptors in the small intestine.

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