THE VASOMOTOR CONTROL OF THE LIVER CIRCULATION

Abstract

By the use of a special plethysmograph which permits records to be taken of the volume of the entire liver the following have been established in regard to the vaso-motor control of the hepatic circulation: (1) Stimulation of the post-gangli-onic fibers along the hepatoduodenal artery or of the pre-ganglionic fibers of the splanchnic nerve causes constriction of the terminations of the hepatic artery and of the portal vein. (2) Stimulation of the peripheral vagus has no effect on liver volume. (3) The liver constricts during pressor and dilates during depressor reflexes; both reactions are abolished by cutting the postganglionic fibers of the hepatic plexus. (4) The liver constricts powerfully during asphyxia; this is inaugurated through its nerves and reinforced and sustained by the asphyxial secretion of epinephrine. (5) Hemorrhage induces a contraction of liver volume which may be sufficient to sustain the blood pressure; this reaction, too, is abolished by section of the hepatic plexus.