Chapter-1 / Physiological Foundations - WHNLive Public Library

old°z-/ImitMW mode of calcu/aflonCC~~---_.L- ---lL.... __'1 q:: const. (saturated)JlI.JfO~~ ~lIIlStduiaIitIl.solunilrti f~(f/I1!(/fJ I(1/I1!flnn/lKJ.9nn:I: 101lg."!JID./1'1./4,~5:,1,; ~r r"A~~~~7 Vtl: I~~, :&1'q:: ex .C(unsaturated)r-----tl--II-/,.~2I .,. II1II- P. ' f--fr.• r. . _'lUI' iL~ r z I ! P~24 6 100III1III1fJFig. 90 Model of a single capillary with coaxial 02diffusion field. Symbols as for the solution of thediffusion field equation, see Table 10r = radius, measured from the capillary axisc =concentration, Le. 02 partial pressureo =diffusion coefficientq =consumption of permeated substrateQ= consumption constant = 6q/6clIRc =capillary radiusC c = mean concentration in the capillaryRt = radius{ at the crossing pointC t = concentration between CI and CIIR z =fictitious supply area, Krogh's cylinderFig. 91 Characteristic curve of the function _q~ =f (P0 2), Le. oxygen consumption in dependence ofoxygen partial pressure in tissue. Idealized extrapolatiaccording to data given in [164]. Parameters: P0z. atcapillary wall, 45 mmHg; T*z =time constant to the~consumptionin tissue 1 ;TA = time constant of the ~­exchange circulationltissue 1 ; q02 is defined as Id O 2consumed per mg dry weight of tissue and hour1 For the definition of these parameters, see [2, 163]H~ = H~).J aRt) = Hankel's function at the pointo (R t, C t)Table 9 Mean values for the 02 consumption, the blood flow rate and the arteriovenous difference in the 02 concentrationin the blood of various human organs at 37 0 C [32]Organ tissue 0 2 consumption Q02 Blood flow rate BF a/v differenceml/100 g/min ml/1oo g/min vol.-%1 Myocardium at rest 8 to 10 80 to 90 10 to 15under severephysical strain to 30 300 to 400 to 17----------------------------------------------------------~ Kidney cortexouter marrowinner marrowtotal9 to 106 to 6.50.3 to 0.55.5 to 6.5400 to 500120254002,0 to 2.551 to 21.5 to 2.5------------------------------------------_._--------------3 Brain cortexmarrowtotal8 to 1013.580 to 11015 to 2550 to 60104 t066 to 7----------------------------------------------------------4 Liver total 4.5 60 to 100 3 to 3.5----------------------------------------------------------5 Spleen total 0.6 to 0.8 100 to 130 0.5 to 0.8----------------------------------------------------------6 Skeletal mu Ie at re tworking hard0.25 to 0.5to 102 t04to 5010 to 15----------------------------------------------------------7----------------------------------------------------------ood 0.008 to 0.01