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 structures of the gastrointestinal system absorbs iron and bile salts?

• A. Ileum
• B. Jejunum
• C. Colon
• D. Duodenum

Correct answer: A

Rationale: The correct answer is the Ileum. The Ileum is the final section of the small intestine where the absorption of key nutrients such as iron and bile salts occurs. The Jejunum mainly absorbs nutrients like carbohydrates and proteins, while the Duodenum primarily facilitates the absorption of minerals and vitamins. The Colon's main function is to absorb water and electrolytes, not iron and bile salts. Therefore, choices B, C, and D are incorrect.

3. Is the parietal pleura a visceral membrane?

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

Correct answer: B

Rationale: The statement that the parietal pleura is a visceral membrane is false. The parietal pleura is actually a membrane that lines the thoracic cavity and is responsible for protecting and cushioning the lungs. Visceral pleura, on the other hand, is the membrane that covers the surface of the lungs. Therefore, the parietal pleura is not a visceral membrane, making the correct answer 'False.' Choices C and D are not relevant as the question is asking for a true/false statement.

4. 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.

5. What is assimilation?

• A. changing absorbed substances into different chemical forms
• B. breaking down foods into nutrients that the body can absorb
• C. eliminating waste from the body
• D. an increase in body size without a change in overall shape

Correct answer: A

Rationale: Assimilation is the process of changing absorbed substances into different chemical forms. It occurs after nutrients from food are absorbed into the bloodstream and used by the body. Choice B, breaking down foods into nutrients that the body can absorb, refers to the process of digestion rather than assimilation. Choice C, eliminating waste from the body, describes the process of excretion. Choice D, an increase in body size without a change in overall shape, does not accurately define assimilation.

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