Nokea
How much does the inspired O2 concentration have to be raised to abolish the hypoxaemia?
- A. 5%
- B. 7%
- C. 10%
- D. 15%
Correct Answer: B
Rationale: The correct answer is B (7%). To abolish hypoxemia, inspired O2 concentration needs to be increased sufficiently to raise arterial oxygen levels. A 7% increase is generally effective in achieving this without causing oxygen toxicity. Choices A, C, and D are incorrect because a 5% increase may not be enough to abolish hypoxemia, a 10% increase can lead to oxygen toxicity, and a 15% increase is excessive and unnecessary for treating hypoxemia. Therefore, option B is the most appropriate and balanced choice for addressing hypoxemia effectively.
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How many layers of pleura have
- A. 2
- B. visceral
- C. Parietal
- D. all of the above
Correct Answer: A
Rationale: Step 1: Pleura is a thin membrane that surrounds the lungs and lines the chest cavity.
Step 2: There are two layers of pleura - visceral (inner layer covering the lungs) and parietal (outer layer lining the chest cavity).
Step 3: The correct answer is A (2), because there are only two layers of pleura.
Summary: Choice B and C are incorrect because they each represent only one layer of pleura, whereas the correct answer A encompasses both layers. Choice D is incorrect because it includes all options, which is not accurate in this case.
Which of the following describes a correct order of structures in the respiratory passageways?
- A. pharynx, trachea, larynx, bronchi, bronchioles
- B. larynx, pharynx, trachea, bronchioles, bronchi
- C. trachea, pharynx, larynx, bronchi, bronchioles
- D. pharynx, larynx, trachea, bronchi, bronchioles
Correct Answer: D
Rationale: The correct order of structures in the respiratory passageways is D: pharynx, larynx, trachea, bronchi, bronchioles. This is the correct order because air enters the body through the pharynx, then passes through the larynx (voice box), followed by the trachea (windpipe), which branches into the bronchi, and then further divides into bronchioles. The other choices are incorrect because they do not follow the natural flow of air through the respiratory system. Choice A has the incorrect order starting with the pharynx, followed by the trachea, larynx, bronchi, and bronchioles. Choice B starts with the larynx, then pharynx, trachea, bronchioles, and bronchi, which is out of sequence. Choice C begins with the trachea, then pharynx, larynx, bronchi, and bronchioles, which is also incorrect
The obstructive lung disease in which connective tissues are lost, alveolar surfaces are damaged, and the respiratory surface is reduced is called
- A. asthma
- B. bronchitis
- C. emphysema
- D. tuberculosis
Correct Answer: C
Rationale: Emphysema is the correct answer because it is characterized by the destruction of alveolar walls and connective tissues in the lungs, leading to reduced respiratory surface area. Asthma is characterized by airway inflammation and bronchoconstriction. Bronchitis is inflammation of the bronchial tubes. Tuberculosis is a bacterial infection affecting the lungs. Emphysema best fits the description provided in the question.
A nurse is working in a walk-in clinic. She has been alerted that there is an outbreak of tuberculosis (TB). Which of the following clients entering the clinic today is most likely to have TB?
- A. A 16-year-old female high school student
- B. A 33-year-old day-care worker.
- C. A 43-year-old homeless man with a history of alcoholism.
- D. A 54-year-old businessman.
Correct Answer: C
Rationale: The correct answer is C, a 43-year-old homeless man with a history of alcoholism. This choice is most likely to have TB because individuals who are homeless and have a history of alcoholism are at higher risk for TB due to weakened immune systems and living conditions. Homelessness and alcoholism increase the likelihood of exposure to TB.
Explanation for other choices:
A: A 16-year-old female high school student - Less likely to have TB compared to homeless individuals with risk factors.
B: A 33-year-old day-care worker - Possible but less likely compared to the homeless man with a history of alcoholism.
D: A 54-year-old businessman - Least likely to have TB compared to the homeless individual with risk factors.
Which of these factors does not affect hemoglobin's affinity for oxygen?
- A. RBC metabolic activity
- B. temperature
- C. electrolyte balance
- D. the PO2 of blood
Correct Answer: C
Rationale: The correct answer is C: electrolyte balance. Hemoglobin's affinity for oxygen is primarily influenced by factors such as pH, temperature, and the partial pressure of oxygen (PO2). Electrolyte balance, on the other hand, does not directly impact hemoglobin's ability to bind with oxygen. Changes in electrolyte levels may affect overall blood composition but do not directly alter hemoglobin's oxygen-binding capacity. Therefore, electrolyte balance does not affect hemoglobin's affinity for oxygen, making it the correct choice. RBC metabolic activity can impact oxygen release from hemoglobin, temperature can affect hemoglobin's oxygen-binding capacity, and the PO2 of blood directly influences oxygen binding to hemoglobin.