Diffusion limitation vs perfusion limitation — Flashcards

Flashcard 1: In exercise, O2 exhibits _____-limited gas exchange

Answer: perfusion

Extra: O2 is perfusion-limited in both resting and exercise states in healthy individuals at sea level. It becomes diffusion-limited in conditions like pulmonary fibrosis or during exercise at high altitude where the partial pressure gradient is reduced.

Flashcard 2: N2O exhibits _____-limited gas exchange

Answer: perfusion

Flashcard 3: CO2 exhibits _____-limited gas exchange

Answer: perfusion

Flashcard 4: When patients have diseased lung tissue (e.g. fibrosis/emphysema) O2 transfer becomes _____-limited

Answer: diffusion

Flashcard 5: The lung diffusing capacity, DL, is _____ proportional to the alveolar wall thickness

Answer: inversely

Flashcard 6: What is the secondary regulator of cerebral perfusion?

Answer: PO2 - only takes effect during severe hypoxia

Flashcard 7: What is the primary regulator of cerebral perfusion?

Answer: PCO2

Flashcard 8: How long can the brain withstand hypoxia before sustaining irreversible damage?

Answer: 5 minutes

Flashcard 9: COPD, cyanotic congenital heart disease, obstructive sleep apnea, and high altitude cause _____ polycythemia

Answer: physiologic secondary

Extra:  * due to chronic hypoxia Watch Polycythemia [https://dashboard.sketchy.com/study/medical/courses/medical-pathophysiology/units/medical-pathophysiology-myeloid-lymphoid/videos/medical-pathophysiology-myeloid-and-lymphoid-myeloid-disorders-polycythemia?utm_source=anki&utm_medium=partnership&utm_campaign=february_update&utm_content=medical] https://onlinemeded.org?ref=anki 

Flashcard 10: In the _____, HCO3- enters the red blood cells in exchange for Cl-

Answer: lungs

Extra:  Watch associated Bootcamp video [https://app.bootcamp.com/med-school/pulmonology/videos/blood?index=12] https://onlinemeded.org?ref=anki