Nursing Elites

1. 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.

2. What does magnetic resonance imaging use?

• A. X-rays.
• B. a radio antenna.
• C. radioisotopes.
• D. high-frequency sound waves.

Correct answer: D

Rationale: Magnetic resonance imaging (MRI) uses high-frequency sound waves to create detailed images of the inside of the body. X-rays (Choice A) use electromagnetic radiation, not sound waves, making it an incorrect choice. A radio antenna (Choice B) is used for communication, not for MRI imaging. Radioisotopes (Choice C) are used in nuclear medicine imaging techniques, not in MRI scans. Therefore, the correct answer is high-frequency sound waves (Choice D) as they are utilized in MRI technology to produce images.

3. 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.

4. What is the membrane on the surface of a lung called?

• A. visceral pleura
• B. parietal pleura
• C. visceral pericardium
• D. parietal pericardium

Correct answer: A

Rationale: The correct answer is A: visceral pleura. The membrane covering the surface of the lungs is called the visceral pleura. It is a serous membrane that is in direct contact with the lung tissue. Choices B, C, and D are incorrect because the parietal pleura covers the inner surface of the chest wall and diaphragm, the visceral pericardium covers the surface of the heart, and the parietal pericardium is the outer layer of the pericardium surrounding the heart, respectively.

5. Macromolecules are built of?

• A. Monomers
• B. Incorrect
• C. Not Applicable
• D. None of the above

Correct answer: A

Rationale: The correct answer is A: Monomers. Macromolecules are built from smaller subunits called monomers. Monomers join together through chemical reactions to form larger molecules known as macromolecules. Option B is incorrect as it does not provide the accurate information regarding the composition of macromolecules. Option C is not applicable as it does not offer a relevant choice. Option D is incorrect because there is a specific answer related to the composition of macromolecules.

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