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. Calcium concentration in the blood is controlled by which of the following glands?

• A. Hypothalamus gland
• B. Thyroid gland
• C. Pituitary gland
• D. Parathyroid glands

Correct answer: D

Rationale: The correct answer is Parathyroid glands. The parathyroid glands are responsible for regulating calcium levels in the blood by secreting parathyroid hormone (PTH). PTH helps increase calcium levels in the blood when they are too low. The other glands listed, such as the Hypothalamus, Thyroid, and Pituitary glands, do not directly control calcium concentration in the blood.

3. Paired organs, such as the kidneys or lungs, are said to be

• A. bisexual.
• B. bilingual.
• C. bilateral.
• D. bivalent.

Correct answer: C

Rationale: The correct answer is C: 'bilateral.' Paired organs like the kidneys or lungs are described as bilateral because they occur in pairs on both sides of the body. Option A 'bisexual' refers to having both male and female reproductive organs, which is not the correct term for paired organs. Option B 'bilingual' refers to being able to speak two languages, which is not related to the description of paired organs. Option D 'bivalent' means having two valences, which is also unrelated to the context of paired organs.

4. 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.

5. Lowering the hand by straightening the elbow affects which of the following muscles?

• A. biceps brachii
• B. triceps brachii
• C. brachialis
• D. brachioradialis

Correct answer: B

Rationale: Lowering the hand by straightening the elbow is the action of extending the forearm, which is primarily done by the triceps brachii muscle. The triceps brachii is the main extensor muscle of the elbow joint. The biceps brachii is responsible for flexing the elbow, not extending it, making it an incorrect choice. Brachialis is a strong elbow flexor, and brachioradialis helps in flexing the elbow and pronating the forearm, so they are not the primary muscles involved in straightening the elbow.

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