Fluid exchange in the microcirculation

J_v = Lp S [ (Pc - Pi) - σ*(Πc - Πi) ]

  • Pc - Pi = capillary-interstitial hydrostatic gradient
  • Πc - Πi = capillary-interstitial oncotic pressure gradient

applies in GFR as well?

pressures across capillaries

  • arteriole: 30-40 mmHg
  • 25 mmHg in the middle
  • venule: 10-15mmHg

higher in glomerular capillaries - varies by tissueFF