Flashcards in Respiration Lecture 08: Distribution of Ventilation and Lung Perfusion Deck (16):
low blood oxygen
2 main causes of hypoxemia
1) increase in thickness of diffusion barrier due to i.e. infection, edema, pulmonary hypertension, swelling
2) loss of surface area of diffusion barrier
more negative Ppl --> PTP?
PTP also becomes more negative
Which area of the lung is most ventilated?
basal region due to gravity
Is PO2 greater in apical or basal region?
Is PCO2 greatest in apical or basal region of lung?
Why does L heart generate larger pressure than R heart?
Must supply blood to all of systemic circulation
increased lung volume --> alveoli and capillaries?
Alveoli expand, capillaries tend to collapse
*Gravity prevent regional collapse of pulmonary capillaries*
amt. of time a bollus of blood sits in gas exchange space.
Increased cardiac output --> transit time
What percent of cardiac output goes through pulmonary vasculature?
4 main functions of pulmonary vasculature
1) acts on all blood contents
3) regulates blood enzymes
4) activates/deactivates venous molecules
Ventilation to perfusion ratio (VA/Q)
estimates the match between blood perfusion of a pulmonary capillary around an alveolus and the ventilation of the alveolus
part of systemic circulation that provides oxygenated systemic blood to the bronchi. Doesn't usually get into gas exchange areas