Nursing Elites

1. 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: B

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.

2. Which of the following is not true of organelles?

• A. They carry out specific activities.
• B. They are only present in human cells.
• C. They are composed of aggregates of large molecules.
• D. They are found in many types of cells.

Correct answer: B

Rationale: Organelles are not exclusive to human cells but are present in various types of cells across different organisms. Option B is incorrect as it suggests that organelles are only found in human cells, which is false. Choices A, C, and D are correct statements about organelles. Organelles indeed carry out specific activities, are made up of aggregates of large molecules, and can be found in many types of cells.

3. The anatomy of a body part is closely related to its physiology.

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

Correct answer: A

Rationale: The statement is true. Anatomy and physiology are interconnected fields. Anatomy focuses on the structure of body parts, while physiology deals with the functions of those parts. Understanding the structure (anatomy) of a body part is crucial in comprehending how it functions (physiology). This interrelation is essential for healthcare professionals to diagnose and treat medical conditions effectively. Choice B is incorrect because anatomy and physiology are indeed closely related. Choice C is incorrect as well because the relationship between anatomy and physiology is a fundamental concept in the study of the human body. Choice D is incorrect as the statement is true.

4. Maintaining a stable internal environment typically requires

• A. positive feedback mechanisms.
• B. an unstable outside environment.
• C. decreased atmospheric pressure.
• D. negative feedback mechanisms.

Correct answer: D

Rationale: The correct answer is 'negative feedback mechanisms.' In biological systems, negative feedback mechanisms help maintain homeostasis by counteracting any deviations from the set point. They work to stabilize internal conditions and keep them within a narrow range. On the other hand, positive feedback mechanisms amplify changes and are not involved in maintaining stability. Choice B, 'an unstable outside environment,' is incorrect as internal stability is independent of external conditions like weather. Choice C, 'decreased atmospheric pressure,' is also incorrect as it does not directly relate to internal homeostasis.

5. 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.

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