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. Which of the following valves prevents backflow of blood from the right ventricle into the right atrium of the heart?

• A. Aortic
• B. Tricuspid valve
• C. Pulmonic
• D. Mitral valve

Correct answer: B

Rationale: The correct answer is the tricuspid valve. The tricuspid valve is located between the right atrium and the right ventricle of the heart. Its main function is to prevent the backflow of blood from the right ventricle into the right atrium during the heart's pumping cycle. Choice A, the aortic valve, is responsible for preventing backflow from the aorta into the left ventricle. Choice C, the pulmonic valve, prevents backflow from the pulmonary artery into the right ventricle. Choice D, the mitral valve, prevents backflow from the left ventricle into the left atrium.

3. Temperature is a form of energy, whereas heat is a measurement of the intensity of the temperature.

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

Correct answer: A

Rationale: The statement is true. Temperature is a measure of the average kinetic energy of the particles in a substance, while heat is the transfer of energy from a hotter object to a colder one. Heat is not a measurement of the intensity of temperature, but rather the energy transfer due to a temperature difference. Therefore, the correct answer is True. Choice B (False) is incorrect as the statement is true based on the definitions of temperature and heat.

4. 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.

5. In the early days, healers transitioned from superstition and magic to using natural chemicals in the field of medicine.

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

Correct answer: A

Rationale: The statement is true. The field of medicine evolved as early healers moved away from superstition and magic, instead focusing on natural chemicals to treat illnesses. This transition marked a shift towards a more scientific and evidence-based approach to healthcare. This historical transition is well-documented in the evolution of medicine. Choice B is incorrect because the statement accurately reflects the historical development of medicine. Choice C is incorrect as the historical transition from superstition to natural chemicals is a well-documented aspect of the evolution of medicine. Choice D is incorrect as the statement provided is true.

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