BPK 305 Lecture Notes - Lecture 28: Perfusion, Partial Pressure, Cellular Respiration

• School: Simon Fraser University
• Department: Biomedical Physio & Kines
• Course: BPK 305
• Professor: Damon Poburko

Document Summary

Lecture 28 ventilation-perfusion ii: ve = minute ventilation, va = alveolar ventilation, vd = dead space volume. 3: ex. go for a run and breathe faster -> need more o2, but also making more co2 and need to remove it = breathe faster, paco2 (thus paco2) is inversely proportional to va. Doubling va halves pacos: steady state paco2 = paco2, so hyperventilation -> respiratory alkalosis -> cerebrovascular vasoconstriction -> dizziness. Increase va (increase o2 and decrease co2) increases pao2. The amount of o2 in the alveolus depends on the amount of co2. Estimate regional ventilation by imaging lung distribution of inhaled, radioactive. At frc, pip lower at base of lung so alveoli are underinflated and thus more compliant. So a given pip during inspiration causes greater vl near base of lungs than apex. Va increases from apex to base of lungs due to gravity and posture.