The contact between the human blood and foreign technical apparatus (circulatory) and respiratory assist devices, arti ficial kidneys) leads to changes in the plasmatic and cel lular components of the blood, which have often only been taken as signs of gross but passive blood destruction. There is much evidence to support this notion in parts (mechanical cellolysis of erythrocytes and thrombocytes), however, these changes have to be seen in a broader bio logical context as an organ-specific reaction of the blood. It is an unjustified oversimplification to simply treat the blood as transport...