Pulm circulation Flashcards
(20 cards)
only vascular bed to receive entire CO
pulmonary circulation
O2 supplies to the lung
- bronchial circulation
- pulm circulation
- alveolar gas O2 supply
- -> lung ischemia is rare
which is higher: TPR or PVR (pulm vascular R)
PVR
Afterload RV ___ Afterload LV due t ___
<
pathologic R –> L shunt
reason for slight drop in end-capillary P to arterial P (RV and LV)
bronchial flow - shunt
where does bronchial flow end up
LV
physiological shunt =
sum of normal anatomic shunts + any pathologic intrapulmonary R –> L shunt
when does pathologic intrapulmonary R –> L shunt occur
airways are blocked –> HYPOXEMIA
mean pulmonary arterial pressure > 20
hypertension
mean pulmonary arterial pressure > 25
leads to pulmonary edema –> diffusion problem
pulmonary wedge presssure
pressure in left atrium
Swan Ganz catheter inserted into jugular, brachial, or femoral artery and advanced into _____ measures…
pulmonary artery pressure
basal tone and autoregulation of pulmonary arteries =
- minimal basal tone
- don’t autoregulate
- passive changes in pulmonary vascular resistance
alveolar vs extra-alveolar blood vessels during inspiration
- alveolar are stretched, narrower
- extra-alveolar expand due to negative intrapleural pressure
ventilate with _____ pressure settings b/c
- lowest possible
- w/ mechanical ventilation, alveolar pressure becomes (+) = more chance to collapse
why does hypoxic vasoconstriction happen
to shunt blood to better ventilated region of lung
Ca channel blockers, NO
vasodilators
norepi, increased PCO2/low pH, angiotensin II
vasoconstrictors
blood flow is greatest where in lung and why
- base of lung
- gravity, passive distension
passive distension in lung
more blood, greater pressure in capillaries, greater transmural pressue toward base of lung
