Pulmonary Circulation Oct13 M1 Flashcards
what prof says about pulmonary arteries
carry partially deoxygenated blood
what prof says about pulmonary veins
carry oxygenated blood
what prof says about bronchial veins
carry partially deoxygenated blood
example of physiological shunt
bronchial veins mostly drain into pulmonary veins rather than venous circulation
pulmonary arteries characteristics
thin wall, diameter changes easily with pressures
pulmonary vascular resistane
resistance in pulmonary circulation
what drives movement in pulmonary circulation
Pa (pulm artery) - PLA (left atrium)
something particular about the pulmonary vascular resistance
decreases as flow increases
why PVR decreases as flow increases
alveolar distension
alveolar recruitment
relationship between pressure and flow across the pulmonary circulation
non-linear. at higher flows, the same pressure gradient produces greater increase in flow (bc resistance lower)
how lung volume affects the resistance of pulmonary vessels
alveolar vessels (septum) get narrower extra-alveolar vessels expand
why extra-alveolar vessels expand with change in pressure
because are attached to surrounding lung tissue so traction force
pulm vessels resistance at volume greater than TLC (intra and extra alveolar)
alveolar vessels: R increases
extra-alveolar: R decreases
extra alveolar vessels resistance at volume lower than FRC
increased
what influences pulmonary vascular resistance (diameter) the most (2)
transmural pressure and lung volume