Which of the following is NOT a characteristic feature of alveoli in the lung?

Correct Answer: D

Rationale: Poor blood supply (D) isn't an alveolar feature . Alveoli (300 million) boast a 70 m^2 surface (A), 0.2 μm walls (B), and surfactant (C) to prevent collapse, with rich capillaries (Page 5, Q11J) not poor (D). Efficient O2 diffusion (50 mL/min) demands vascularity. D's falsity unlike A's expanse or C's tension reduction contradicts alveolar design, per document.

Correct Answer: B

Rationale: Oxygen's atmospheric percentage (21%) exceeds CO2's (0.04%) (B), but its solubility in blood (0.024 mL/mmHg/dL) is lower than CO2's (0.57 mL/mmHg/dL) . O2's higher presence drives diffusion (PIO2 ~150 mmHg vs. PICO2 ~0.3 mmHg), yet 98% binds hemoglobin dissolved O2 is minor (1.5% at PaO2 100 mmHg). CO2's solubility aids 10% dissolved transport, with 70% as HCO3-. B's contrast unlike A's reversal matches gas laws and physiology's transport mechanisms.

Correct Answer: B

Rationale: Surfactant reduces alveolar surface tension (B). From type II cells, it drops tension (30 dynes/cm to 5), preventing collapse (Q9). Pleural pressure (A) stays negative (-5 cm H2O). Alveolar pressure (C) is 0 at rest, unaffected directly. Inspiration eases (D, false), compliance rises (0.2 to 0.5 L/cm H2O). B's role unlike A's irrelevance stabilizes 300 million alveoli, per physiology (Q64).

Correct Answer: D

Rationale: Pneumothorax doesn't increase lung compliance. Lung collapses (Q11), thorax widens (A), reducing VC (C, < 4.8 L) and venous return (B, pressure loss, Q58). Compliance (~0.2 L/cm H2O) drops collapsed lung stiffens, not softens (D). A's expansion, B's cardiac effect, and C's volume loss align with air entry (0 mmHg intrapleural). D's increase unlike A's mechanics contradicts physiology's restrictive shift.

Correct Answer: A

Rationale: In hypoxia with hypercapnia (e.g., COPD), cautious oxygen via a Venturi device (A) is optimal. Hypercapnia reflects COâ‚‚ retention; high Oâ‚‚ (B) risks suppressing the hypoxic drive, worsening COâ‚‚ buildup and acidosis a danger in chronic respiratory failure. Intubation (C) is invasive, reserved for acute failure, not initial management. None' (D) ignores hypoxia's urgency. The Venturi mask delivers precise, low-flow Oâ‚‚ (e.g., 24-35%), correcting hypoxemia without over-oxygenation, balancing Oâ‚‚ saturation (e.g., 88-92%) and COâ‚‚ levels. This approach, rooted in respiratory physiology, prevents ventilatory depression, a key nursing consideration in titrating oxygen therapy for obstructive lung diseases.