자라에 있어서 정맥환류량(靜脈還流量)의 증가(增加)가 심박(心博)에 미치는 영향(影響)
Effects of Increasing the Venous Return on the Heart Rate in the Water Turtle - Myogenic Regulatory Mechanisms in the so-called Bainbridge Reflex -
By the intravenous infusion of saline solution through the postcaval vein, the effects of increasing the venous return on the heart rate were studied in the water turtle (Amyda japonica). The following results were obtained: 1) Prior to saline infusion, when the initial heart rate was below 50~55.min the heart rate was increased by the infusion. When the initial rate was above this value no changes in heart rate were observed following the infusion. 2) When the heart rate was decreased by vagal stimulation, the infusion elicited a remarkable increase in the heart rate. 3) Increased heart rate caused by tile infusion was not affected by vagotomy or sympathectomy. 4) These results suggest that the increase in heart rate secondary to increased venous return is under the control of a myogenic regulatory mechanism, not a neural mechanism.