Nursing Elites

1. What effect does aldosterone secretion have on electrolyte levels?

• A. Calcium levels are decreased
• B. Sodium levels are increased
• C. Potassium levels are increased
• D. Magnesium levels are decreased

Correct answer: Sodium levels are increased

Rationale: Aldosterone is a hormone that primarily acts on the kidneys to increase the reabsorption of sodium and water into the bloodstream. As a result, sodium levels are increased. Choices A, C, and D are incorrect. Aldosterone does not significantly affect calcium, potassium, or magnesium levels.

2. 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: triceps brachii

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.

3. The transition from a hunter-gatherer to an agricultural lifestyle greatly changed the types of diseases and injuries that early peoples suffered.

• A. True
• B. False
• C. Not Sure
• D. All of the above

Correct answer: A

Rationale: The correct answer is True. The transition from a hunter-gatherer to an agricultural lifestyle did indeed greatly change the types of diseases and injuries that early peoples suffered. With the shift to agriculture came increased sedentism, population density, and interaction with domesticated animals, leading to the emergence of new diseases and health challenges. Choice B is incorrect because the statement is true based on historical and archaeological evidence. Choice C is incorrect as there is historical data supporting the impact of this transition. Choice D is incorrect as it is not applicable since all options do not hold true in this context.

4. 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: Uterine contractions during childbirth

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.

5. Which of the following is not an example of a homeostatic mechanism in the human body?

• A. Shivering when the body temperature falls below normal.
• B. Increasing heart rate and force of contraction when blood pressure falls.
• C. Retaining fluid excessively.
• D. Secreting insulin after a meal to return blood sugar concentration toward normal.

Correct answer: C: Retaining fluid excessively.

Rationale: The correct answer is C. Homeostatic mechanisms aim to maintain internal stability within the body. Choices A, B, and D all represent examples of homeostatic mechanisms. Shivering helps generate heat to raise body temperature back to normal levels. Increasing heart rate and force of contraction work to restore blood pressure. Insulin secretion after a meal helps regulate blood sugar levels. On the other hand, retaining fluid excessively can lead to fluid imbalance rather than maintaining internal stability, making it the incorrect choice.

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