The continuity equation shows that for an incompressible fluid volume, in the absence of any sources or sinks, the net flux must be zero. In other words, if no new fluid is being added and none is escaping, the amount of fluid entering an area must be equal to the amount of fluid leaving the area. One practical result is that the velocity of fluid increases as the cross section of the pipe decreases. This is important in determining the dynamics of blood circulation.
