2Structure of Capillary Wall Figure 16-2; Guyton and Hall
3Interstitium and Interstitial Fluid Figure 16-4; Guyton and Hall
4Determinants of Net Fluid Movement across Capillaries Figure 16-5; Guyton and HallCapillary hydrostatic pressure (Pc)-tends to force fluid outward through the capillary membrane.Interstitial fluid pressure (Pif)- opposes filtration when value is positive.
5Determinants of Net Fluid Movement across Capillaries Figure 16-5; Guyton and HallPlasma colloid osmotic pressure ( c)- opposes filtration causing osmosis of water inward through the membraneInterstitial fluid colloid pressure ( if) promotes filtration by causing osmosis of fluid outward through the membraneNP = Pc - c - Pif + if
6Plasma Proteins and Colloid Osmotic Pressure 75% of the total colloid osmotic pressure of plasma results from the presence of albumin and 25% is due to globulins.gm/dl p(mmHg)AlbuminGlobulinsFibrinogenTotal
7Determinants of Net Fluid Movement Across Capillaries Figure 16-5; Guyton and HallFiltration rate = net filtration pressure (NFP) multiplied by the filtration coefficientFiltration coefficient (Kf) is a product of surface area times the hydraulic conductivity of membrane
8Forces Causing Filtration at the Arteriole End of the Capillary mmHgForces tending to move fluid outward:Capillary pressure 30Negative interstitial free fluid pressure 3Interstitial fluid colloid osmotic pressure 8TOTAL OUTWARD FORCEForces tending to move fluid inward:Plasma colloid osmotic pressure 28TOTAL INWARD FORCESummation of forces:OutwardInwardNET OUTWARD FORCE
9Forces Causing Reabsorption at the Venous End of the Capillary mmHgForces tending to move fluid inward:Plasma colloid osmotic pressure 28TOTAL INWARD FORCEForces tending to move fluid outward:Capillary pressure 10Negative interstitial free fluid pressureInterstitial fluid colloid osmotic pressureTOTAL OUTWARD FORCE 21Summation of forces:Outward 21Inward 28NET INWARD FORCE 7
10Net Starling Forces in Capillaries mmHgMean forces tending to move fluid outward: Mean Capillary pressure 17.3 Negative interstitial free fluid pressure 3.0 Interstitial fluid colloid osmotic pressure 8.0 TOTAL OUTWARD FORCE 28.3 Mean force tending to move fluid inward: Plasma colloid osmotic pressure 28.0 TOTAL INWARD FORCE 28.0 Summation of mean forces: Outward 28.3 Inward 28.0 NET OUTWARD FORCE 0.3
11Net Starling Forces in Capillaries Figure opener; Guyton and HallNet filtration pressure of .3 mmHg which causes a net filtration rate of 2ml/min for entire body.
12Question Utilizing the data below, calculate the rate of net fluid movement across the capillary wall:Pressures (in mmHg)Plasma colloid osmotic = 20Capillary hydrostatic = 20Venous hydrostatic = 5Arterial = 80Interstitial hydrostatic = -5Interstitial colloid osmotic = 5Filtration coefficient = 10 ml/min/mmHga. 0 ml/min d. 100 ml/min (Reabsorption)b. 10 ml/min (Filtration) e. 10 ml/min (Reabsorption)c. 100 ml/min (Filtration)
14Determinants of Lymph Flow The degree of activity of the lymphatic pumpsmooth muscle filaments in lymph vessel cause them to contractexternal compression also contributes to lymphatic pumpingFigure 16-11; Guyton and Hall
15Determinants of Lymph Flow Interstitial fluid hydrostatic pressureLymph FlowFigure 16-9; Guyton and HallFigure 16-10; Guyton and Hall