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. An investigator who conducts an experiment to determine how temperature changes affect the rate at which the heart beats is most likely a(n)

• A. anatomist.
• B. physiologist.
• C. chemist.
• D. biochemist.

Correct answer: B

Rationale: The correct answer is 'physiologist.' A physiologist studies how the body functions under normal and abnormal conditions, including how temperature changes can affect physiological processes like heart rate. An anatomist focuses on the structure of organisms rather than their functions, making choice A incorrect. Choices C and D are also incorrect as they are more related to the study of chemicals and biochemistry, which are not directly relevant to investigating the effects of temperature on heart rate.

3. Is oxygen the primary raw material for new living material?

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

Correct answer: B

Rationale: While oxygen is essential for many living organisms, it is not the primary raw material for new living material. The primary raw materials for new living material are carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur, collectively known as CHNOPS elements. These elements are the building blocks of biological molecules and are essential for life. Therefore, the correct answer is False. Choices C and D are incorrect because the primary raw materials for new living material are well-established in biology.

4. The anatomical term that indicates a structure close to the surface is

• A. anterior
• B. proximal
• C. superficial
• D. superior

Correct answer: C

Rationale: The correct answer is 'superficial.' In anatomy, the term 'superficial' refers to a structure that is close to the surface of the body. Choice A, 'anterior,' refers to the front of the body, not specifically to depth. Choice B, 'proximal,' refers to a structure that is closer to the point of attachment or trunk of the body. Choice D, 'superior,' indicates a structure that is above or higher in position.

5. Which of the following cardiac valves prevents blood from returning to the left ventricle of the heart?

• A. pulmonic
• B. mitral
• C. tricuspid
• D. aortic

Correct answer: D

Rationale: The correct answer is the aortic valve. The aortic valve is located between the left ventricle and the aorta, preventing the backflow of blood into the left ventricle once it has been pumped out during systole. Choice A, pulmonic, is incorrect as it is associated with the right side of the heart. Choice B, mitral, is incorrect as it is the valve between the left atrium and ventricle. Choice C, tricuspid, is incorrect as it is located between the right atrium and ventricle.

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