Abstract
The present overview is intended to serve several purposes. It highlights efforts over the years to resolve the difficult key issues raised by August Krogh in the 1930s and by the urgent need created in the 1940s and 1950s by World War II to come to grips with the basic problems underlying the collapse of tissue perfusion in the syndrome of circulatory shock. The complex operational issues raised by circulatory insufficiency at the systemic, as well as the local tissue level, during the shock syndrome, are used as a framework to keep in perspective the impact of advances in methodology, ultrastructure, and in recent years in molecular biology on microvascular research. In view of the current continuing need to integrate the newly emerging body of in vitro information into specific aspects of the operation of the peripheral vascular tree, emphasis is placed on the advances in dealing with data provided by in vivo microscopy of selected tissues.
This overall review has made it clear that a top priority remains the need to separate the effects of systemic and locally derived readjustments, and to identify the basis for the substantial differences in cellular behavior exhibited by the vascular and perivascular components of the various organs and tissues of the body that can serve as predisposing factors in regional pathophysiology.