BIOL 1840U Lecture Notes - Hypoxic Pulmonary Vasoconstriction, Perfusion, Angiotensin
Document Summary
_ gas: dco2 = 20do2; dco = do2, diffusing capacity (conductance) = 1/resistance. Dl(gas) = (net rate of transfer) / (partial pressure gradient alv cap) i. 1 (cid:247) (cid:246) (cid:231: whole lung: lung volume => pvr (b/c of effect on alveolar vessels) Zones of lung: flow/pressure gradients, b/c of hydrostatic gradient blood flow > at bottom than top, palv has much less of a gradient than parterial, zone 1, zone 2. If height of lung is greater than pa(mean arterial pressure), pa > pa > pv capillary is squeezed shut => no flow (behaves like dead space) Pa > pa > pv => flow determined solely by difference between pa & Pa > pv > pa => flow is determined by gradient between pa & pv: zone 3, exercise pa => zone 3 & zone 2 expand, recruiting zone 1 vessels.
