Nursing Elites

1. Homeostasis exists if concentrations of water, nutrients, and oxygen in the body and heat and pressure __________.

• A. decrease steadily
• B. remain within certain limited ranges
• C. increase when the body is stressed
• D. fluctuate greatly between very high and low values

Correct answer: B

Rationale: Homeostasis is the body's ability to maintain stable internal conditions despite external changes. To achieve this balance, concentrations of essential substances must remain within specific ranges. Choice A is incorrect because decreasing concentrations would not maintain stability. Choice C is incorrect as increasing concentrations when the body is stressed would disrupt homeostasis. Choice D is incorrect as fluctuating greatly between high and low values would also not support the body's stability. Therefore, the correct answer is B, as it aligns with the concept of homeostasis by emphasizing the need for stability within certain limits.

2. Reproduction is the change in body characteristics over time.

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

Correct answer: B

Rationale: Reproduction is the process by which living organisms produce offspring of the same kind. It is not related to changes in body characteristics over time. Therefore, the statement is false. Choices C and D are also incorrect as they do not align with the definition of reproduction.

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: 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.

4. Does aging begin in the fetus?

• A. Yes
• B. No
• C. Not Sure
• D. None of the above

Correct answer: A

Rationale: Aging does begin in the fetus. The aging process starts even before birth due to cellular changes and the passage of time. The cells in a fetus undergo growth, division, and aging from the moment of conception. This continual process of cellular aging continues throughout life. Therefore, the statement is true. Choice B is incorrect because aging does initiate during the fetal stage. Choice C is incorrect as the process of aging commences in the fetus. Choice D is incorrect as the correct answer is 'Yes,' indicating that aging does start in the fetus.

5. What causes wrinkled and sagging skin?

• A. Drinking too much water
• B. Heredity alone
• C. Loss of subcutaneous fat and reduced levels of elastin and collagen
• D. Excess subcutaneous fat

Correct answer: C

Rationale: Wrinkled and sagging skin is primarily caused by the loss of subcutaneous fat and reduced levels of elastin and collagen in the skin. Choice A is incorrect as drinking too much water does not lead to wrinkled and sagging skin. Choice B is incorrect because heredity alone does not cause this condition. Excess subcutaneous fat, as mentioned in Choice D, can contribute to a different skin appearance, such as puffiness, but not wrinkled and sagging skin.

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