Regulation of the peripheral circulation.

Needless to say, the different vascular circuits and their consecutive sections are designed to meet the particular demands of their tissues, both as to the range of blood supply and as to how this supply is distributed and put into efficient exchange within the tissue. Not only the dimensions of the resistance vessels but also the capillary permeability and surface area are therefore closely tailored both for local nutritional demands and in some tissues for such special functions as secretion and absorption (Folkow and Neil, I97I).