ABSTRACT
In this chapter, we will focus our discussion on the transport of solutes in biological systems. Solute transport occurs both through bulk ¢uid motion, also known as convection, and by solute diffusion due to the presence of solute concentration gradients. In biological as well as synthetic membrane systems, the diffusion of a solute will also be affected by the presence of a variety of heterogeneous structures. For example, solutes will need to diffuse through porous structures, such as the capillary wall or a polymeric membrane, around or through cells within the extravascular space, and through the interstitial ¢uid containing a variety of macromolecules.
