Volume of air left after maximum forceful expiration in human lung is
- A. Total lung capacity
- B. Residual volume
- C. Vital capacity
- D. Tidal volume
Correct Answer: B
Rationale: The correct answer is B: Residual volume. After maximum forceful expiration, residual volume is the volume of air left in the lungs to prevent lung collapse. Total lung capacity (A) is the maximum amount of air the lungs can hold. Vital capacity (C) is the maximum amount of air that can be exhaled after a maximum inhalation. Tidal volume (D) is the volume of air moved in and out of the lungs during normal breathing, not after a forceful expiration.
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In human beings the number of lobes in right and left lungs is
- A. 2 and 3
- B. 2 and 2
- C. 3 and 2
- D. 4 and 2
Correct Answer: C
Rationale: The correct answer is C: 3 and 2. The right lung has 3 lobes (upper, middle, lower), while the left lung has 2 lobes (upper and lower). This is due to the presence of the heart on the left side, occupying space that limits the left lung to 2 lobes. Option A is incorrect as the left lung has only 2 lobes. Option B is incorrect as both lungs have different numbers of lobes. Option D is incorrect as the right lung typically has 3 lobes, not 4.
Most oxygen in the blood is transported
- A. as gas dissolved in plasma
- B. as oxyhemoglobin
- C. as carboxyhemoglobin
- D. as bicarbonate
Correct Answer: B
Rationale: The correct answer is B: as oxyhemoglobin. Oxygen is primarily carried in the blood by binding to hemoglobin in red blood cells to form oxyhemoglobin. This allows for efficient transport of oxygen to tissues. Choice A is incorrect because only a small amount of oxygen is dissolved in plasma. Choice C is incorrect as carboxyhemoglobin refers to carbon monoxide binding to hemoglobin, not oxygen. Choice D is incorrect as the majority of carbon dioxide is transported as bicarbonate, not oxygen.
A nurse instructs a female client to use the pursed-lip method of breathing and the client asks the nurse about the purpose of this type of breathing. The nurse responds, knowing that the primary purpose of pursed-lip breathing is to:
- A. Promote oxygen intake.
- B. Strengthen the diaphragm.
- C. Strengthen the intercostal muscles.
- D. Promote carbon dioxide elimination.
Correct Answer: D
Rationale: The correct answer is D: Promote carbon dioxide elimination. Pursed-lip breathing is a technique used to slow down breathing and help control shortness of breath. By exhaling through pursed lips, it creates back-pressure in the airways, allowing more time for the lungs to empty and facilitating better removal of carbon dioxide. This helps improve oxygenation by optimizing the gas exchange process. Choices A, B, and C are incorrect because pursed-lip breathing primarily focuses on improving ventilation and gas exchange, not specifically on increasing oxygen intake or strengthening specific respiratory muscles.
A nurse reviews the arterial blood gas results of a client and notes the following: pH 7.45, PCO2 30, HCO3 20. The nurse analyzes these results as indicating which condition?
- A. Metabolic acidosis, compensated
- B. Respiratory alkalosis, fully compensated
- C. Metabolic alkalosis, uncompensated
- D. Respiratory acidosis, uncompensated
Correct Answer: B
Rationale: The correct answer is B: Respiratory alkalosis, fully compensated. The pH is elevated (alkalosis) at 7.45. The low PCO2 of 30 indicates respiratory alkalosis. The HCO3 level of 20 is slightly below normal, indicating metabolic compensation. The body has compensated for the respiratory alkalosis by reducing the HCO3 level. Choices A, C, and D are incorrect because they do not align with the given ABG results. A (Metabolic acidosis, compensated) would have low pH and HCO3 levels. C (Metabolic alkalosis, uncompensated) would have high pH and HCO3 levels. D (Respiratory acidosis, uncompensated) would have high PCO2 and low pH.
The partial pressure of oxygen in atmospheric air at sea level is
- A. greater than the partial pressure of oxygen in atmospheric air at the top of Mt. Everest
- B. less than the partial pressure of oxygen in atmospheric air at the top of Mt. Everest
- C. equal to the partial pressure of oxygen in atmospheric air at the top of Mt. Everest
- D. equal to the sum of partial pressures from carbon dioxide and nitrogen
Correct Answer: A
Rationale: The correct answer is A because the partial pressure of oxygen decreases with increasing altitude due to the decrease in atmospheric pressure. At sea level, the atmospheric pressure is higher, resulting in a higher partial pressure of oxygen compared to the top of Mt. Everest. Choice B is incorrect because the partial pressure of oxygen is not higher at higher altitudes. Choice C is incorrect because the partial pressure of oxygen is not equal at sea level and Mt. Everest. Choice D is incorrect because the question specifically asks about the partial pressure of oxygen only, not the sum of partial pressures from other gases.