Nursing Elites

1. A spring with a spring constant of 100 N/m is stretched 0.2 m from its equilibrium position. What is the potential energy stored in the spring?

• A. 2 J
• B. 4 J
• C. 8 J
• D. 20 J

Correct answer: B

Rationale: Potential energy in a spring is calculated as 1/2 * k * x², where k is the spring constant and x is the displacement from equilibrium. Therefore, the potential energy is 1/2 * 100 N/m * (0.2 m)² = 4 J.

2. Which of the following organs is NOT directly involved in the mechanical breakdown of food?

• A. Mouth
• B. Stomach
• C. Small intestine
• D. Esophagus

Correct answer: D

Rationale: The correct answer is D, esophagus. The esophagus is a muscular tube that connects the mouth to the stomach, but it is not directly involved in the mechanical breakdown of food. The mouth is responsible for the initial mechanical breakdown of food through chewing, the stomach further breaks down food through muscular contractions, and the small intestine aids in the digestion process. However, the esophagus primarily serves to transport chewed food from the mouth to the stomach via peristaltic movements, without actively breaking down the food itself.

3. What is the feedback mechanism in the endocrine system that helps maintain hormone balance?

• A. Positive feedback, where a hormone stimulates its own release
• B. Negative feedback, where a hormone suppresses its own release
• C. Cascade effect, where one hormone triggers the release of another
• D. Dual hormone system, where two hormones work together

Correct answer: B

Rationale: The correct answer is B: Negative feedback, where a hormone suppresses its own release. In the endocrine system, negative feedback is a crucial mechanism that helps maintain hormone balance. When hormone levels rise, they signal the body to decrease further hormone production, preventing an excess. This ensures that hormone levels stay within a narrow range, promoting stability and homeostasis. Positive feedback (option A) would lead to an amplification of hormone release, which is not ideal for maintaining balance. Cascade effect (option C) involves a sequential activation of hormones but does not directly regulate hormone levels. Dual hormone system (option D) refers to two hormones working together but doesn't specifically address the feedback mechanism for maintaining hormone balance.

4. Which type of wave does not require a medium for propagation?

• A. Transverse wave
• B. Longitudinal wave
• C. Mechanical wave
• D. Electromagnetic wave

Correct answer: D

Rationale: Electromagnetic waves, like light and radio waves, can travel through a vacuum, unlike mechanical waves (sound, water waves) that require a medium to vibrate and transmit energy.

5. The innate immune system provides a non-specific first line of defense. What are some physical barriers that contribute to the innate immune system?

• A. Antibodies
• B. Phagocytes
• C. Skin and mucous membranes
• D. Memory B cells

Correct answer: C

Rationale: The correct answer is C: "Skin and mucous membranes." The innate immune system consists of physical barriers, such as the skin and mucous membranes, that act as the first line of defense against pathogens. These barriers prevent pathogens from entering the body and play a crucial role in protecting against infections. Antibodies (option A) are part of the adaptive immune response, not the innate immune system. Phagocytes (option B) are cells that engulf and destroy pathogens, which are part of the innate immune system. Memory B cells (option D) are specific to the adaptive immune response and are not considered part of the innate immunity that provides the initial, non-specific defense.

6. Which type of energy is associated with the random motion of particles in a substance?

• A. Potential energy
• B. Mechanical energy
• C. Thermal energy
• D. Chemical energy

Correct answer: c

Rationale: Thermal energy is related to the random motion of particles in a substance and is associated with temperature.

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