ATI LPN
Respiratory System Questions Questions
Question 1 of 5
The lungs are covered by a two-layer membrane called the:
Correct Answer: A
Rationale: The pleura (A) is the two-layer membrane (visceral/parietal) covering the lungs, per the key reducing friction (15 mL fluid). The diaphragm (B) is a muscle, not a covering. The respiratory membrane (C) is the alveolar-capillary interface (0.2 μm). Intercostal muscles (D) aid breathing, not encasing lungs. Pleura's serous layers (5-10 μm thick) allow 6-8 L/min expansion, per anatomy unlike B's contraction, C's diffusion role, or D's support, A's protective sheath is the lung's hallmark.
Question 2 of 5
The parents of a child with bronchopulmonary dysplasia (BPD) are receiving home instructions on tracheotomy care. With regards to suctioning, the nurse should advise the parents that each suction pass should take no longer than:
Correct Answer: B
Rationale: 5 seconds (B) is the advised suction time for BPD tracheotomy, per document (implied pediatric norm). Short passes (5-10 s) clear mucus (e.g., 5-10 mL) without hypoxia (SpOâ‚‚ drop <5%). 2 seconds (A) is too brief, 10-15 seconds (C, D) risk desaturation. B's balance per AAP protects fragile BPD lungs (Oâ‚‚ need 30%), unlike D's excess.
Question 3 of 5
Surface tension of the alveolar fluid is reduced by the presence of
Correct Answer: C
Rationale: Surfactant, a lipoprotein mix from type II alveolar cells, reduces alveolar fluid's surface tension, preventing collapse (atelectasis) by lowering cohesive forces of water molecules lining alveoli. Mucus traps particles in airways, not affecting alveolar tension. Sebum, an oily skin secretion, is irrelevant here. Water increases tension surfactant counters this. By decreasing tension, surfactant stabilizes alveoli, especially smaller ones, easing inflation and preventing lung collapse post-exhalation. This is vital for efficient gas exchange, a cornerstone of lung mechanics, critical in conditions like respiratory distress syndrome where surfactant deficiency causes breathing difficulty, underscoring its role in pulmonary stability.
Question 4 of 5
Most oxygen in the blood is transported
Correct Answer: B
Rationale: Most oxygen (~98%) is transported as oxyhemoglobin, bound to hemoglobin in red blood cells, each molecule carrying four Oâ‚‚ vastly more than dissolved in plasma (~2%, ~0.3 mL/100 mL). Carboxyhemoglobin forms with carbon monoxide, not Oâ‚‚ transport. Bicarbonate (HCO₃â») carries COâ‚‚, not Oâ‚‚. Oxyhemoglobin's high capacity, shifting with POâ‚‚ (oxygen-hemoglobin curve), ensures efficient Oâ‚‚ delivery to tissues, key in oxygen transport physiology, critical in anemia or hypoxia where binding capacity or Oâ‚‚ levels drop, impacting cellular supply.
Question 5 of 5
When teaching the parents of an older infant with CF (cystic fibrosis) about the type of diet the child should consume, which of the following would be most appropriate?
Correct Answer: D
Rationale: A high-calorie diet (D) is most appropriate for an older infant with cystic fibrosis (CF). CF's thick mucus obstructs pancreatic ducts, impairing enzyme release, causing malabsorption of fats and proteins requiring extra calories (often 120-150% of normal) to support growth. Moderate fat, not high (B), aids absorption with enzyme supplements; low protein (A) risks malnutrition; low carbohydrate (C) limits energy. Thick mucus also increases respiratory work, boosting caloric needs. This diet, paired with enzymes, counters CF's nutritional deficits, key in nursing education to prevent failure to thrive, a common CF challenge.