)血流阻力 血流阻力:血液在血管内流动所遇到的阻力 来源于血液内部质点之间以及血液 质点与管壁之间的摩擦力. Q=(P1-P2)R R=8mL/Tr4 Q=5mL/sec @=10 mL/sec Q=5mL/sec Q=0 D FIGURE 20-3. The flow, Q, of fluid through a tube connecting two reservoirs, R, and Rz, is proportional to the differ. ence between the pressure at the inflow end (P) and the pressure at the outflow end(P)of the tube. A, When R2 is empty, fluid flows from R, to R2 at a rate proportional to the pressure in R,. B, When the fluid level in R, is increased twofold, the flow increases proportionately. C, Flow from R, to R2 is proportional to the difference between the pres sures in R, and R2. D, When pressure in Rz rises to equal the pressure in Ri, flow ceases.血流阻力: 血液在血管内流动所遇到的阻力. 来源于血液内部质点之间以及血液 质点与管壁之间的摩擦力. Q =(P1－P2 )/R R=8L/r4 （二）血流阻力