Reaction types of regional redistribution of blood.

Changes are described in relative contents of blood in tissues and organs, usable for evaluation of regional redistribution of blood caused by various factors influencing the organism. Despite specific characters of such changes, several basic types were identified which may represent several phases of a general nonspecfic reation, whose character varies in dependence on the actual degree of stimulation or lesion. In the first phase the relative contents of blood increase in the brain, heart, lungs, and in the muscle and bone tissues of the head, neck , and thorax. The second phase is characterized by increased blood content in the liver. In the third phase blood is mobilized from the liver and redistributed into tissues exposed to functional loads, with marked anaemization of the liver. In the fourth phase the regional redistribution becomes pathological. Experiments were made in male albino rats exposed to various stresses [blood loss, confinement in a tight box, treadmill running, various types of general anaesthesia, and others].