Sympathetic nervous activity after hemorrhage.

The role of the sympathetic nervous system in acute hemorrhage and hemorrhagic shock has been extensively investigated in recent years (Chien, 1967). Indirect evidence as well as direct recording of the action potentials in the different pre- and postganglionic sympathetic nerves showed, that there is a hyperactivity of the sympathetic system in hemorrhagic shock (Beck et.al. 1955; Chien, 1964; Corazza et.al.l963/a, 1963/b;Fedina et.al.1965; Floyd et.al. 1952; Gemandt et.al.1947; Gootman et.al.1969; 1970; Thamer et.al.1969) . Comparing the results obtained by direct recording of action potentials in sympathetic nerves, it can be seen, that there are no real discrepancies between the data of various authors in respect of the sympathetic hyperactivity and its time course in acute hemorrhage and hemorrhagic shock. Relatively little is known however, about the control of the sympathetic nervous activity in hemorrhagic shock.