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一、直立性低血压的原因 体位由卧位变为立位时由于重力作用下肢血压上升,头部血压下降。因静脉壁具有伸展性,血液移向低处,向心性静脉回流减少,心搏出量减少。此时心肺以及动脉压感受器发挥作用;交感神经兴奋引起动静脉收缩,心率增加;脏器血流分布也发生改变以维持循环平衡。
First, the cause of orthostatic hypotension Position from the supine to the standing position due to gravity the lower extremity blood pressure, head pressure drops. Due to the extensibility of the vein wall, the blood moves to the lower, reduced ventricular return, reduced cardiac output. Heart and lung and arterial pressure receptor play a role at this time; sympathetic excitation caused arteriovenous contraction, heart rate increased; organ blood flow distribution also changed to maintain the balance of circulation.