ABSTRACT
This chapter describes the major vital systems that cooperate with each other in supporting life. Their function can be described as being integrative, in that they are continually adjusted according to need and because changes in one system are usually accompanied by changes in the others. The adequacy of the function of the vital support systems is best assessed by a few key variables, the magnitude of which can readily be determined in the blood. When the osmotic pressure of blood is artificially lowered, as for example by diluting blood with distilled water, cells swell and lyse. The water dilutes the osmotic strength of the solution of proteins and ions. A major function of the plasma proteins is to provide colloid osmotic pressure in the blood and thereby to reduce water movement out of the capillary beds and into tissue. Blood coagulation results from conversion of fibrinogen to fibrin, under the influence of an enzyme called thrombin.
