The concentration of nitrogen in the earth's atmosphere is approximately
- A. 78 percent.
- B. 66 percent.
- C. 50 percent
- D. 33 percent
Correct Answer: A
Rationale: The correct answer is A: 78 percent. The rationale is based on the fact that nitrogen makes up approximately 78% of the Earth's atmosphere. This is a well-known scientific fact supported by various studies and measurements. Option B, C, and D are incorrect as they do not align with the established data on the composition of the Earth's atmosphere. Nitrogen is the most abundant gas in the atmosphere, followed by oxygen, which is around 21%. Therefore, option A is the correct choice based on scientific evidence and consensus.
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A nurse is preparing to obtain a sputum specimen from a male client. Which of the following nursing actions will facilitate obtaining the specimen?
- A. Limiting fluid.
- B. Having the client take deep breaths.
- C. Asking the client to spit into the collection container.
- D. Asking the client to obtain the specimen after eating.
Correct Answer: B
Rationale: The correct answer is B: Having the client take deep breaths. This action facilitates obtaining a sputum specimen by helping the client to cough and expectorate sputum effectively. Deep breaths help to mobilize secretions, making it easier for the client to produce a quality specimen. Limiting fluid intake (choice A) can lead to dehydration and thickening of secretions, making it harder to obtain a specimen. Asking the client to spit into the container (choice C) may result in contamination with saliva. Asking the client to obtain the specimen after eating (choice D) can introduce food particles into the specimen, affecting the accuracy of the test.
Which of the following structures most is responsible for determining pulmonary resistance?
- A. visceral and parietal pleura
- B. Trachea
- C. Bronchi
- D. Bronchioles
Correct Answer: D
Rationale: The correct answer is D: Bronchioles. Bronchioles are the smallest airways in the lungs and play a crucial role in determining pulmonary resistance. They have smooth muscle surrounding them, which can contract or relax to regulate airflow and resistance. Constriction of bronchioles increases resistance, while dilation decreases it. Visceral and parietal pleura (A) are membranes that cover the lungs and chest wall, not directly involved in determining pulmonary resistance. The trachea (B) and bronchi (C) are larger airways that mainly serve as conduits for air passage and do not have as significant an impact on resistance as the bronchioles do.
Which of the following nursing activities is most important when a client comes back from a respiratory test if they have respiratory problems?
- A. Allow the client to rest
- B. Assess the client’s airway
- C. Teach the client important information
- D. Teach the family about respiratory disease
Correct Answer: B
Rationale: The correct answer is B. Assessing the airway is critical immediately after a respiratory test, especially if the client has pre-existing respiratory issues. A (rest) is secondary until stability is confirmed. C and D involve education, which is important but not urgent compared to ensuring airway patency.
Exhaling into a paper bag and rebreathing the exhaled air would be expected to
- A. alert the brain.
- B. increase the breathing rate.
- C. stimulate the carotid bodies.
- D. b and c only
Correct Answer: D
Rationale: Exhaling into a paper bag and rebreathing the exhaled air leads to an increase in carbon dioxide levels in the body. This increase stimulates the carotid bodies, which detect changes in blood chemistry, leading to an increase in breathing rate. This process does not directly alert the brain, as high carbon dioxide levels typically cause drowsiness rather than alertness. Therefore, the correct answer is D, as it correctly identifies the effects of rebreathing on both breathing rate and carotid body stimulation. Choice A is incorrect because rebreathing does not directly alert the brain. Choice B is incorrect as rebreathing actually decreases the need for increased breathing rate initially. Choice C alone is incorrect as it does not address the effect on breathing rate.
Carbonic anhydrase in the RBC is the fastest enzyme and it decomposes in one second for fast action. Its concentration in the blood is due to the presence of
- A. Plasma
- B. Carbon dioxide
- C. Sodium ions
- D. Hemoglobin
Correct Answer: D
Rationale: The correct answer is D: Hemoglobin. Carbonic anhydrase is an enzyme found in red blood cells that rapidly catalyzes the conversion of carbon dioxide into bicarbonate ions. Hemoglobin plays a crucial role in transporting carbon dioxide in the blood. The high concentration of hemoglobin in red blood cells allows for efficient binding and transport of carbon dioxide, leading to the need for a rapid enzyme like carbonic anhydrase to facilitate its conversion. Plasma (choice A) does not directly influence the concentration of carbonic anhydrase. Carbon dioxide (choice B) is the substrate for carbonic anhydrase, not the reason for its concentration. Sodium ions (choice C) do not directly affect the action of carbonic anhydrase in red blood cells.