Nursing Elites

1. 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: In the endocrine system, negative feedback is the mechanism by which hormone levels are regulated. When hormone levels reach a certain threshold, they signal the body to stop producing more of that hormone, thus maintaining a balance. Negative feedback (option B) is the correct answer as it helps in preventing overproduction of hormones by suppressing their own release. Positive feedback (option A) would lead to an excessive production of hormones, disrupting the balance. The cascade effect (option C) involves one hormone triggering the release of another but does not directly regulate hormone levels. The dual hormone system (option D) refers to two hormones working together but does not specifically address the feedback mechanism for maintaining hormone balance.

2. What is the function of valves in arteries?

• A. To maintain high blood pressure for the proper diffusion of nutrients in capillaries.
• B. To prevent backflow of blood due to high pressure away from the heart.
• C. As a vestigial trait from evolution, like the appendix, that serves no purpose.
• D. Valves are absent in arteries but present in veins.

Correct answer: B

Rationale: Valves in arteries serve the crucial function of preventing backflow of blood. Arteries carry blood at high pressure away from the heart, and the valves ensure that blood flows in one direction, towards the capillaries, to maintain efficient circulation. Without these valves, there would be a risk of blood flowing backward, compromising the effectiveness of blood circulation in the body. Choices A, C, and D are incorrect. Choice A incorrectly suggests that valves maintain high blood pressure for nutrient diffusion in capillaries, which is not their function. Choice C inaccurately compares valves to vestigial traits, like the appendix, implying they serve no purpose, which is untrue. Choice D is incorrect as valves are indeed present in arteries to regulate blood flow, not just in veins.

3. Muscle soreness after exercise is often caused by microscopic tears in muscle fibers. This is called

• A. Atrophy
• B. Hypertrophy
• C. DOMS (Delayed Onset Muscle Soreness)
• D. Spasm

Correct answer: C

Rationale: Muscle soreness after exercise is often caused by microscopic tears in muscle fibers, leading to Delayed Onset Muscle Soreness (DOMS). Atrophy refers to the wasting away of muscle tissue, hypertrophy is the increase in muscle size, and spasm is an involuntary contraction of a muscle. DOMS typically occurs 24 to 72 hours after intense exercise and is characterized by muscle stiffness, tenderness, and reduced range of motion. It is a normal response to unfamiliar or strenuous physical activity and indicates that the muscles are adapting to the workload. Therefore, the correct answer is C (DOMS) as it specifically describes the phenomenon of muscle soreness resulting from microscopic tears in muscle fibers, distinguishing it from the other choices which refer to different physiological processes or conditions.

4. If you have a rectangle with a width of 5 inches and a length of 10 inches and scale it by a factor of 2, what will the new perimeter be?

• A. 30 inches
• B. 40 inches
• C. 60 inches
• D. 50 inches

Correct answer: C

Rationale: When a rectangle is scaled by a factor of 2, both the length and width are multiplied by 2. The new dimensions become width = 5 * 2 = 10 inches and length = 10 * 2 = 20 inches. Therefore, the new perimeter is calculated as 2 * (10 + 20) = 60 inches. Choice A, B, and D are incorrect as they do not reflect the correct calculation based on scaling the dimensions of the rectangle.

5. What property of a wave determines its pitch in sound waves?

• A. Amplitude
• B. Frequency
• C. Wavelength
• D. Speed

Correct answer: B

Rationale: The pitch of a sound wave is determined by its frequency. Frequency is the number of cycles of a wave that occur in a given time period. Higher frequencies correspond to higher pitches, while lower frequencies correspond to lower pitches. Amplitude refers to the intensity or loudness of a sound wave, wavelength is the distance between two consecutive points in a wave, and speed is the rate at which a wave travels through a medium. Therefore, in sound waves, it is the frequency that primarily determines the pitch, making option B the correct answer.

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