Abstract
The effects of artificial bleeding upon the systemic blood pressure, as measured with a cannula inserted into the femoral artery, and the blood flow of the internal carotid artery, as measured with the heated thermocouple, were studied in rabbits anesthetized with Nembutal and immobilized with D-tubocurarine. It was revealed that as long as the amount of the blood removed was within a certain limit, not only the blood pressure, but also the blood flow remained fairly constant. It was especially noteworthy that the tendency to maintain a constant blood flow was far more powerful than that to keep a stable blood pressure. These phenomena were abolished by sectioning the sinus nerve on both sides. From these results it was inferred that the informations conveyed in the sinus nerve served two purposes, that is, to keep the systemic blood pressure as well as the blood flow of the internal carotid constant.
