In an asthmatic attack, which of the following is expected?

Correct Answer: C

Rationale: Asthma, an obstructive disease, features reversible bronchoconstriction, inflammation, and mucus production during attacks. Narrowed airways increase resistance, especially on expiration, when dynamic compression worsens airflow, producing wheezing louder and more prolonged than on inspiration, making that statement false. Work of breathing rises as respiratory muscles (e.g., diaphragm) work harder against resistance and trapped air, a consistent expectation. Bronchodilators (e.g., albuterol) are standard treatment, relaxing bronchial smooth muscle, not contraindicated. FEV1 decreases (e.g., from 80% to 50% predicted) due to obstructed airflow, not increases. Increased work of breathing reflects the effort to overcome narrowed passages, elevating energy expenditure and often leading to accessory muscle use, aligning with asthma's acute physiology where resistance and air trapping dominate, distinguishing it from incorrect options misaligned with clinical presentation.

Correct Answer: D

Rationale: Minute ventilation (VE) = tidal volume (VT) × respiratory rate (RR), fixed at 6 L/min (6000 ml/min). Alveolar ventilation (VA) = (VT - VD) × RR, with anatomic dead space (VD) = 150 ml. For 200 ml at 30/min: VE = 200 × 30 = 6000 ml/min, VA = (200 - 150) × 30 = 50 × 30 = 1500 ml/min. For 300 ml at 20/min: VA = (300 - 150) × 20 = 150 × 20 = 3000 ml/min. For 400 ml at 15/min: VA = (400 - 150) × 15 = 250 × 15 = 3750 ml/min. For 600 ml at 10/min: VA = (600 - 150) × 10 = 450 × 10 = 4500 ml/min. The 600 ml at 10/min maximizes VA (4.5 L/min), as larger VT exceeds VD more, despite lower RR. High RR with low VT wastes ventilation in dead space, reducing VA efficiency. This deeper, slower pattern optimizes gas exchange, making it the best choice.

Correct Answer: D

Rationale: Pneumothorax introduces air into the pleural space, negating intrapleural pressure (~-4 mmHg), collapsing the lung via elastic recoil and expanding the chest wall outward via its recoil increasing thoracic diameter, true. Venous return drops as positive pleural pressure (e.g., tension pneumothorax) compresses vena cava, reducing preload true. Vital capacity (VC) falls as collapsed lung limits exhalable volume (e.g., from 4-5 L) true. Lung compliance (C = ΔV / ΔP) doesn't increase collapsed lung tissue isn't more stretchable; compliance is a lung property unaffected by deflation, effectively zero in collapse, not raised. The false notion of increased compliance misrepresents pneumothorax, where pressure loss, not elasticity, drives effects, making it the untrue statement amid accurate mechanical outcomes.

Correct Answer: A

Rationale: Functional residual capacity (FRC) = expiratory reserve volume (ERV) + residual volume (RV). RV = 1.0 L via helium dilution. The spirogram shows vital capacity (VC = IRV + VT + ERV) from max inhalation to max exhalation. Without the figure, assume typical female values: VC ~4 L, TLC ~5 L. FRC is post-normal expiration; if ERV (exhalable beyond tidal) is ~1 L (common for young women), FRC = ERV + RV = 1 + 1 = 2.0 L. Higher FRC (2.5-3.5 L) fits larger frames or males (~3 L). The 2.0 L aligns with RV and minimal ERV, plausible for a 22-year-old female, reflecting resting volume per standard physiology.

Correct Answer: B

Rationale: The Coriolis effect is an apparent deflection of moving objects (e.g., air, water) due to Earth's rotation, not a true force but an inertial effect in a rotating frame. In the Northern Hemisphere, it deflects right; Southern, left proportional to velocity and latitude (2ωv sinφ). Gravity drives weight, not deflection false. Pressure gradients from solar heating drive winds, not Coriolis false. Friction (e.g., surface drag) opposes motion, not deflects false. Coriolis shapes weather patterns (e.g., cyclones), per geophysical fluid dynamics (e.g., Holton), making it the best description, distinct from physical forces or heating effects.