Lecture 10: Ventilation- Perfusion Relationships Flashcards
Hypoxemia
low blood oxygen which induces minute ventialtion
Hypoxia hypoxemia
due to decreased PO2
Alveolar hypoventilation
decrease ventilation doesn’t provide sufficient refreshing of alveolar gas to maintain PAO2
Causes of alveolar hypventialtion
obstruction of airway
paralysis of respiratory muscles
decreased respiratory drive from CNS
Treat hypo ventilation with?
PIO2 and increase ventialtion
Diffusion limitation
increasing difficulty fr oxygen to diffuse from alveoli to blood b thickening of diffusion barrier
Shunt
flow of blood from right atria to L, heart bypassing gas exchange are or blood flowing past unventilated regions
venous blood mixing with blood returning from the lungs
Does PIO2 have any effect on shunt?
NO
Narrowing of one airway and i normal airway
ventilation will decrease on restricted side- causing some gas exchange to occur but not enough
increased ventilation doesn’t work
Alveoulus
Po2 drives Co2
Blood
CO2 drives PO2