Nokea
Which of the following gas mixture is used by Divers to prevent Oxygen toxicity
- A. Oxygen and CO2
- B. Oxygen and Nitrogen
- C. Oxygen and rare gases
- D. Oxygen, CO2 and Nitrogen
Correct Answer: B
Rationale: The correct answer is B: Oxygen and Nitrogen. This gas mixture is used by divers to prevent Oxygen toxicity because it closely mimics the composition of the air we breathe. Oxygen toxicity can occur at high partial pressures of Oxygen, which can lead to seizures and other serious health issues. Choices A, C, and D are incorrect because CO2 and rare gases are not typically used in diving gas mixtures, and including CO2 in the mixture can increase the risk of Oxygen toxicity. Nitrogen is used as a diluent to reduce the partial pressure of Oxygen, making it safer for divers.
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The most important factor in determining the percent of oxygen saturation of hemoglobin
- A. The partial pressure of o2
- B. acidity
- C. the partial of co2
Correct Answer: A
Rationale: The correct answer is A: The partial pressure of O2. Oxygen saturation of hemoglobin is directly related to the partial pressure of oxygen in the blood. As the partial pressure of O2 increases, more oxygen binds to hemoglobin, leading to higher oxygen saturation. Acidity (choice B) and the partial pressure of CO2 (choice C) can influence the oxygen-hemoglobin dissociation curve, but they are not the primary factors determining oxygen saturation. Choice D is incomplete and not relevant to the question.
The normal rate and depth of breathing is established by the ________ center(s).
- A. apneustic
- B. pneumotaxic
- C. DRG and VRG
- D. expiratory
Correct Answer: C
Rationale: The correct answer is C because the Dorsal Respiratory Group (DRG) and Ventral Respiratory Group (VRG) are the centers in the brainstem responsible for controlling the rate and depth of breathing. The DRG primarily regulates inspiration, while the VRG is involved in both inspiration and expiration. The apneustic and pneumotaxic centers (choices A and B) are subregions within the pons that modulate the activity of the DRG and VRG but do not establish the baseline rate and depth of breathing. The expiratory center (choice D) is responsible for controlling only the expiratory phase of breathing and is not involved in setting the normal rate and depth of breathing.
Why may an ice collar be ordered for a client who is undergoing drainage of a peritonsillar abscess?
- A. To reduce swelling and pain
- B. To help the client drink fluids
- C. To prevent respiratory obstruction
- D. To prevent excessive bleeding
Correct Answer: A
Rationale: The correct answer is A. An ice collar reduces swelling and pain by constricting blood vessels and numbing the area. B (helping the client drink fluids) is unrelated. C (preventing respiratory obstruction) is not the primary purpose of an ice collar. D (preventing excessive bleeding) is managed differently, usually with direct pressure or medication.
Inhibition of medulla oblongata chemoreceptors and respiratory muscles has what effect on respiratory rate, elimination of CO2 at alveoli, and arterial PCO2?
- A. increased respiratory rate, increased elimination of CO2 at alveoli, and increased arterial
PCO2 - B. increased respiratory rate, decreased elimination of CO2 at alveoli, and decreased arterial
PCO2 - C. increased respiratory rate, increased elimination of CO2 at alveoli, and decreased arterial
PCO2 - D. decreased respiratory rate, decreased elimination of CO2 at alveoli, and increased arterial
PCO2
Correct Answer: D
Rationale: The correct answer is D. Inhibition of medulla oblongata chemoreceptors and respiratory muscles would decrease respiratory rate, leading to decreased elimination of CO2 at alveoli. This would cause an increase in arterial PCO2 due to less CO2 being removed from the body. Therefore, choice D is correct.
Choices A, B, and C are incorrect because they do not align with the physiological effects of inhibiting the medulla oblongata chemoreceptors and respiratory muscles. Option A suggests an increase in respiratory rate and elimination of CO2, which goes against the expected decrease in these parameters. Option B proposes an increase in respiratory rate but a decrease in CO2 elimination and arterial PCO2, which is inconsistent with the expected outcomes. Option C suggests an increase in respiratory rate and CO2 elimination but a decrease in arterial PCO2, which does not follow the logic of the question.
The physician orders a PFT. The patient asks you how the test is performed. The best response is:
- A. A tube is inserted into lungs while the patient is asleep to expand his/her lungs to their full capacity.
- B. The patient breathes through a mouthpiece into a spirometer until all air in lungs is expelled. Then the patient will take a deep breath through the mouthpiece. This is done three times and a computer calculates the capacity of lungs.
- C. The patient breathes into a spirometer to measure lung capacity.
- D. A computer is used to measure volume and vital capacity.
Correct Answer: B
Rationale: The correct answer is B. Pulmonary function tests involve breathing into a spirometer to measure lung volumes and capacities. A is incorrect as no tube is inserted. C is incomplete. D focuses only on the computer aspect without explaining the procedure.