A new approach to modelling microcirculatory transport and exchange is introduced and developed with specific reference to skeletal muscle. The objective is to describe the large-scale interaction of a great number of differently perfused capillary groups and to interpret phenomena observed in a whole organ in terms of processes occurring within individual capillaries. We consider fluid exchange and the associated macromolecular transport, the exchange of small metabolites carried in the plasma, and oxygen transport to tissue.