Nursing Elites

1. What is homeostasis?

• A. The inability to keep body weight within normal limits.
• B. Room temperature decreasing because a window is open.
• C. Ingestion of more food than needed.
• D. The tendency of the body to maintain a stable internal environment.

Correct answer: D

Rationale: The correct answer is D: Homeostasis refers to the body's ability to maintain a stable internal environment despite external changes. Choices A, B, and C are incorrect. Choice A describes obesity, choice B describes a specific scenario with room temperature, and choice C refers to overeating, which is not related to homeostasis.

2. Which of the following characteristics of life and their descriptions are correct?

• A. Responsiveness - detecting and responding to changes in the environment
• B. Assimilation - incorporating absorbed substances into the body
• C. Respiration - obtaining energy from food molecules through oxygen
• D. Circulation - the movement of substances in body fluids

Correct answer: D

Rationale: The correct answer is D: Circulation - the movement of substances in body fluids. Circulation refers to the movement of substances like nutrients, gases, and wastes in body fluids to and from cells. Choice A is incorrect because responsiveness is about detecting and responding to changes in the environment, not obtaining and using oxygen. Choice B is incorrect because assimilation is the process of incorporating absorbed substances into the body, not changing them into chemically different forms. Choice C is incorrect because respiration is the process of obtaining energy from food molecules through oxygen, not the obtaining and using oxygen itself.

3. 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: A

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.

4. 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.

5. The maintenance of a steady body temperature in the face of fluctuating environmental conditions illustrates homeostasis.

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

Correct answer: A

Rationale: The correct answer is True. Homeostasis is the body's ability to maintain a stable internal environment despite external changes. In this case, the maintenance of a steady body temperature despite fluctuations in environmental conditions is a clear example of homeostasis. The body regulates temperature through processes like sweating when it's hot and shivering when it's cold. Choices B, C, and D are incorrect because the statement provided does indeed illustrate the concept of homeostasis, making them inaccurate.

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