ATI LPN
Exam Questions on Respiratory System Questions
Question 1 of 5
Which of the following is the function of the diaphragm in expiration?
Correct Answer: B
Rationale: Relaxation (B) is the diaphragm's role in expiration . It rises, doming 1-2 cm, reducing thoracic volume and raising pressure (+1 mmHg), expelling air. Contraction (C) drives inspiration. Energy (A) is cellular, not diaphragmatic. Exchange (D) occurs in alveoli. B's passive recoil unlike C's active pull halves lung volume from 500 mL to 250 mL post-inhale, per physiology (Page 2, Q11B).
Question 2 of 5
At the end of normal quiet expiration, just before the start of inspiration, the lungs are said to be in:
Correct Answer: C
Rationale: After quiet expiration, lungs rest at functional residual capacity (FRC, C) . FRC (~2.5 L) is RV (~1.2 L) plus ERV (~1.3 L) air remaining post-tidal exhale (Vt ~500 mL). RV (A) is after forced expiration. ERV (B) is expirable reserve. IRV (D) is inspiratory reserve (~3 L). At FRC, diaphragm relaxes, intrapleural pressure is -5 cm H2O, and alveolar pressure is 0 mmHg no airflow. C's balance unlike A's minimal volume defines the resting state, per lung volume dynamics (Q28).
Question 3 of 5
At the end of quiet respiration, muscles are relaxed and lungs content represents.
Correct Answer: C
Rationale: Post-quiet expiration, lungs are at FRC (~2.5 L) . Muscles relax, balancing lung inward and chest outward recoil (Q2). RV (A) is post-forced (~1.2 L). ERV (B) is reserve (~1.3 L). IRV (D) is inspiratory reserve (~3 L). FRC RV + ERV is resting volume, with intrapleural pressure -5 cm H2O, unlike A's minimal or D's inspiratory state, per physiology (Q17).
Question 4 of 5
The work of breathing is:
Correct Answer: A
Rationale: Work of breathing inversely ties to compliance. Work = pressure × volume; low compliance (e.g., fibrosis, < 0.1 L/cm H2O) demands more pressure (Q40). Exercise raises work (B, false) via demand (O2 use 1-5%). Resistance (C, false) increases it (asthma, Q8). Fibrosis hikes work (D, false, Q1). A's relation unlike B's static claim matches energy cost (~1-2% basal metabolism), per physiology.
Question 5 of 5
In acute diaphragmatic pleurisy involving the central part of the diaphragm, the patient is likely to complain of pain in:
Correct Answer: A
Rationale: Acute diaphragmatic pleurisy, inflammation of the pleural lining over the diaphragm's central portion, typically causes referred pain to the neck and shoulder (A) via the phrenic nerve (C3-C5), which innervates the diaphragm and shares dermatomes with the supraclavicular region. Lateral chest pain (B) aligns with parietal pleura irritation, not central diaphragmatic. Central chest pain (C) suggests mediastinal or cardiac issues, not diaphragmatic referral. Interscapular pain (D) lacks nerve linkage here, and right lower quadrant pain ties to abdominal pathology, not pleural. This referred pattern, distinct from local chest wall pain, is key in diagnosing diaphragmatic involvement e.g., in pneumonia or subphrenic abscess guiding imaging or intervention, a critical chest pain differentiation in clinical practice.