Practice Test Geeks(CRE) Certified Respiratory Educator Practice Test
← All CRE Flashcard Decks

Respiratory System Anatomy & Physiology Flashcards

7 cards from real CRE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Respiratory System Anatomy & Physiology flashcards as text

  1. Which structure prevents food from entering the larynx during swallowing?

    Answer: Epiglottis

    The epiglottis folds down over the laryngeal inlet during swallowing to direct food and liquid into the esophagus rather than the trachea.

  2. In the alveolar gas equation, if PaCO₂ is 40 mmHg and FiO₂ is 0.21 at sea level, what is the approximate PAO₂?

    Answer: 100 mmHg

    Using the simplified alveolar gas equation: PAO₂ = (713 × 0.21) − (40/0.8) ≈ 149.7 − 50 ≈ 100 mmHg under normal conditions.

  3. Hypoxic pulmonary vasoconstriction (HPV) serves which primary physiological purpose?

    Answer: Divert blood from poorly ventilated lung units to better-ventilated areas

    HPV redirects blood flow away from hypoxic, underventilated alveoli toward better-ventilated regions, thereby optimizing ventilation-perfusion matching.

  4. The 'butterfly' or 'bat-wing' pattern on chest X-ray in pulmonary edema is caused by fluid accumulating primarily in the:

    Answer: Perihilar interstitium and alveoli

    Pulmonary edema fluid preferentially accumulates in the perihilar regions due to loose connective tissue, producing the classic butterfly shadow on X-ray.

  5. Which bronchopulmonary segment of the right lower lobe is most dependent in the supine position and most prone to aspiration?

    Answer: Superior segment

    The superior segment (S6) of the right lower lobe is the most gravity-dependent in a supine patient and thus most susceptible to aspiration pneumonia.

  6. Bohr's equation calculates dead space ventilation ratio (VD/VT). Which value is used in its numerator?

    Answer: Arterial CO₂ minus mixed expired CO₂

    Bohr's equation: VD/VT = (PaCO₂ − PeCO₂) / PaCO₂, where the numerator is the difference between arterial and mixed expired CO₂ tensions.

  7. At a normal V/Q ratio of 0.8, which statement is true?

    Answer: Perfusion slightly exceeds alveolar ventilation

    A V/Q of 0.8 means alveolar ventilation (4 L/min) is slightly less than cardiac output (5 L/min), so perfusion modestly exceeds ventilation under normal resting conditions.