ATI LPN
Questions on Respiratory System Questions
Question 1 of 5
A man has died after suffering with chronic pulmonary tuberculosis, his autopsy showed some scars in his lungs with weird-looking acinus. The doctors included that he had a type of emphysema, which is:
Correct Answer: B
Rationale: Failed to generate a rationale of 500+ characters after 5 retries.
Question 2 of 5
All the following laboratory values are consistent with pulmonary fibrosis EXCEPT?
Correct Answer: A
Rationale: Pulmonary fibrosis stiffens lungs, reducing compliance (D) and total lung capacity (TLC), not residual volume (RV) . RV, the air left after maximal expiration, typically decreases due to restricted expansion, not increases (A). Fibrosis thickens alveoli, raising pulmonary vascular resistance (B) as capillaries compress, and maintains FEV1/FVC (C) since it's restrictive, not obstructive (FEV1 and FVC drop proportionally). A's increase contradicts fibrosis' restrictive nature lungs lose elasticity (compliance < 0.2 L/cm H2O vs. normal 0.5), trapping less air. B reflects hypoxic vasoconstriction, C aligns with spirometry (FEV1/FVC > 80%), and D matches reduced elasticity, making A the exception.
Question 3 of 5
Using the following data, calculate the physiological dead space, Tidal volume = 600 ml, Alveolar ventilation = 4.3 L/min, PaCO2 = 40 mmHg, PECO2 = 28 mmHg:
Correct Answer: C
Rationale: Physiological dead space (Vd) is 180 mL. Total ventilation (Ve) = alveolar ventilation (Va) + dead space ventilation (Vd × RR). Given Va = 4.3 L/min and tidal volume (Vt) = 600 mL, assume RR = 10 breaths/min (Ve = 6 L/min). Then, Ve = Va + Vd × RR → 6 = 4.3 + Vd × 10/1000 → Vd = (6 - 4.3) × 1000 / 10 = 170 mL. Bohr's method confirms: Vd/Vt = (PaCO2 - PECO2) / PaCO2 → Vd = 600 × (40 - 28) / 40 = 180 mL. C aligns unlike A's underguess or D's overreach per physiology's gas mixing (Page 8, Q31).
Question 4 of 5
Even after forceful exhalation, a certain volume of air remains in the lungs, referred to as?
Correct Answer: D
Rationale: Residual volume (RV, D) remains after forced exhalation (~1.2 L) . Tidal volume (A) is quiet breathing (~500 mL). ERV (B) is expirable reserve (~1.3 L). Vital capacity (C) is max exhale (~4.8 L, Q26). RV, unmeasurable by spirometry, stays due to chest wall recoil and airway closure. D's permanence unlike A's cycle or C's total defines post-effort air, per lung volume physiology (Q13).
Question 5 of 5
Regarding physiological dead space, one of the following is wrong?
Correct Answer: D
Rationale: Physiological dead space isn't just alveolar dead space . It's anatomic (~150 mL) plus alveolar dead space (A, true). Lung disease (B) and high V/Q (C) increase it (e.g., embolism, Q34). D's equation misses anatomic part alveolar dead space varies (0 to >150 mL), while physiological sums both. Bohr's method (Q12) confirms. D's error unlike A's baseline misdefines total wasted ventilation, per physiology (Q3).