Rabinovici N, Navot N
Surg Gynecol Obstet. 1980 Dec;151(6):753-63.
Factors affecting blood movement in the main vessels of the venous system and the changes in pressure and flow values in the vena cava and portal and hepatic veins were simultaneously recorded and related to the phases of the respiratory cycle. The experiments were done in rabbits subjected to nembutal anesthesia, with open abdomen, closed chest and spontaneous respiration. The results indicate an asymmetric pressure gradient in the vena cava centered around the diaphragm with larger pressure differences in the thoracic segment; no pressure gradient in the portal vein, and a sharp gradient of possible functional significance at the caval end of the hepatic veins. Portal, hepatic and abdominal caval pressures were positive, but above the diaphragm, vena cava pressure values were predominantly negative. Flow was continuous, unequally distributed throughout the components and fluctuating alternatively during one respiratory cycle. Maximal pressure and flow values in the portal and hepatic veins were concomitant with the lowest values in the vena cava and closely related to respiration. The distribution of opposite pressure and flow values within the components and their integration during one respiratory cycle suggest that, in the process of venous return, each component and each segment fulfills simultaneously different functions co-ordinated by respiration and cardiac activity.
记录了影响静脉系统主要血管中血液流动的因素以及腔静脉、门静脉和肝静脉中压力和流量值的变化，并将其与呼吸周期的各阶段相关联。实验在接受戊巴比妥麻醉、腹部开放、胸部封闭且自主呼吸的兔子身上进行。结果表明，腔静脉中以膈肌为中心存在不对称压力梯度，胸段压力差更大；门静脉中无压力梯度，而在肝静脉腔静脉端存在具有潜在功能意义的陡峭梯度。门静脉、肝静脉和腹段腔静脉压力为正，但在膈肌上方，腔静脉压力值主要为负。血流是连续的，在各组成部分中分布不均，且在一个呼吸周期中交替波动。门静脉和肝静脉中的最大压力和流量值与腔静脉中的最低值同时出现，且与呼吸密切相关。各组成部分内相反压力和流量值的分布及其在一个呼吸周期中的整合表明，在静脉回流过程中，每个组成部分和每个节段同时履行由呼吸和心脏活动协调的不同功能。
