Nursing Elites

1. In negative feedback mechanisms, changes away from the normal state

• A. stimulate changes in the same direction
• B. inhibit all body reactions
• C. stimulate changes in the opposite direction
• D. stimulate a reduction in all body requirements

Correct answer: C

Rationale: In negative feedback mechanisms, changes away from the normal state stimulate changes in the opposite direction. This is a fundamental concept in biological systems where the response to a stimulus opposes the initial change, helping to maintain homeostasis. Choice A is incorrect because negative feedback does not stimulate changes in the same direction. Choice B is incorrect because negative feedback does not inhibit all body reactions, but rather specific responses. Choice D is incorrect because negative feedback does not stimulate a reduction in all body requirements, but rather adjusts specific functions to restore balance.

2. 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.

3. What is the most useful application of ultrasonography for diagnostic examination?

• A. dense organs, such as bones.
• B. air-filled organs, such as lungs.
• C. soft internal structures, such as fetuses.
• D. microscopic structures.

Correct answer: C

Rationale: Ultrasonography is a medical imaging technique that uses sound waves to visualize internal body structures. It is particularly effective for examining soft tissues like organs, blood vessels, and fetuses. Choice A is incorrect because bones are better visualized using techniques like X-rays. Choice B is incorrect as air-filled organs like lungs are not well visualized with ultrasound due to air being a poor conductor of sound waves. Choice D is incorrect since ultrasonography cannot visualize structures at a microscopic level, as it is used for larger internal structures.

4. Do chromosomes get longer as a cell ages?

• A. TRUE
• B. FALSE
• C. Not Sure
• D. None of the above

Correct answer: B

Rationale: Chromosomes do not get longer as a cell ages. In fact, chromosomes condense and become more compact during cell division to ensure proper segregation. Choice A is incorrect because chromosomes do not elongate with age. Choice C is not the correct answer as there is scientific evidence to support that chromosomes do not lengthen over time. Choice D is not the right option as the correct answer is 'False' in this case.

5. Which of the following is a result of stimulation of the sympathetic nervous system?

• A. decreased blood flow to the skeletal muscles
• B. increased cardiac output
• C. decreased respiratory rate
• D. increased urinary output

Correct answer: B

Rationale: Stimulation of the sympathetic nervous system leads to an increase in cardiac output. When the sympathetic nervous system is activated, it causes the heart to beat faster and with more force, leading to an increased cardiac output. Choices A, C, and D are incorrect because the sympathetic nervous system does not cause decreased blood flow to the skeletal muscles, decreased respiratory rate, or increased urinary output.

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