Nursing Elites

1. 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.

2. 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.

3. Which of the following substances is involved in the destruction of ingested pathogens?

• A. lymphatic fluid
• B. stomach acid
• C. bicarbonate
• D. lipase

Correct answer: B

Rationale: The correct answer is stomach acid. Stomach acid, also known as gastric acid, plays a crucial role in destroying ingested pathogens due to its high acidity. The low pH of stomach acid helps to kill bacteria and other pathogens that may be present in the food we consume. Lymphatic fluid is involved in immune function and fat absorption, not pathogen destruction. Bicarbonate is a base that neutralizes stomach acid to prevent damage to the stomach lining. Lipase is an enzyme that aids in the digestion of fats but is not involved in pathogen destruction.

4. What is the term for the upper midportion of the abdomen?

• A. hypochondriac
• B. iliac
• C. hypogastric
• D. epigastric

Correct answer: D

Rationale: The correct answer is "epigastric." The epigastric region is located in the upper midportion of the abdomen, between the hypochondriac regions on either side. Choice A, "hypochondriac," refers to the upper lateral regions of the abdomen beneath the ribs. Choice B, "iliac," pertains to the lower lateral regions of the abdomen. Choice C, "hypogastric," is the lower central region of the abdomen.

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

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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