Abstract
Venous wave and auricular wave investigated in normal respiration, in deep inspiration, in deep expiration, in Muller and Valsalva-test. (1) Depthes of X-valleys in venous waves were always larger in inspiration than in expiration. (2) In auricular wave, depth of Sm-wave was only slightly larger in stoppage of respiration immediately after deep inspiration than in that condition after deep expiration [This does not stand in contradiction with (1): those conditions were thought to be the mixture of deep inspiration and Valsalva-test, or that of deep expiration and Muller-test.]. (3) In Muller-test, depth of Sm-wave was remarkably increased and remarkably decreased in Valsalva-test. These experiments show that venous return is accelerated by the conditions which decrease intrapleural pressure and suppressed by reverse conditions, i.e. venous return, caused by suction-mechanism of heart, is helped by respiration.
