After reading this chapter you should be able to:

explain how terminal arterioles regulate capillary perfusion (10.1);

sketch the key structural differences between three main types of capillary (10.2);

distinguish between the laws governing solute exchange (diffusion) and water exchange (hydraulic flow) (10.3);

list the factors governing the rate of diffusive transport (Fick’s law) (10.3);

define ‘solute permeability’ and explain how a porous membrane affects it (10.4);

name three main categories of solute, based on capillary permeability (10.5-10.7);

outline the special features of the blood-brain barrier (10.8); sketch the concentration profile of a metabolized solute (e.g. glucose) along a capillary and use the sketch to define ‘Fick’s principle’ (cf. law), ‘extraction’ and ‘plasma clearance’ (10.9);

explain the difference between flow-limited and diffusion-limited exchange (10.10);

describe ‘capillary recruitment’, and list other factors that enhance solute exchange in exercising muscle (10.11).