In freezing weather , the exposed parts of the body such as the nose tip , ear lobes , cheeks and chin - may develop frostbites as the skin on them cools and the blood vessels become constricted thus cutting off the blood supply to the area 在寒冷的天气中,暴露于空气中的身体部分,如鼻尖耳垂面颊及颏部会由于皮肤受寒,血管收缩,血液停止供应该范围而出现冻疮。
Si could abolish the effect of lnmma on vasomotion but lnmma did not influence the effect of si on vasomotion . conclusion si can inhibit vasomotion in vasodilation status , but its mechanism is not mediated by endogenous no 在lnmma的有效作用时间内应用si可使被抑制于收缩状态的血管重新扩张,血管运动得以恢复在si的有效作用时间内应用lnmma则不能使处于舒张状态的血管收缩。
In freezing weather , the exposed parts of the body such as the nose tip , ear lobes , cheeks and chin - may develop frostbites as the skin on them cools and the blood vessels become constricted thus cutting off the blood supply to the area 冻疮在寒冷的天气中,暴露于空气中的身体部分,如鼻尖、耳垂、面颊及颏部会由于皮肤受寒,血管收缩,血液停止供应该范围而出现冻疮。
Although regional anesthesia , especially central conduction blockade , produces a favorable sympathectomy and increased limb blood flow , compensatory vasoconstriction in non - anesthetized areas may actually produce vaso - occlusive crises in these areas ( 5 ) 虽然区域麻醉,特别是中枢传导阻滞可产生有效的交感神经阻滞并增加肢体血流,但是非麻醉部位发生代偿性血管收缩,可能使这些部位发生血管阻塞性危象[ 5 ] 。
This effect has been hypothesized to occur through an initial reduction in sympathetic outflow from the central nerous system with its associated decrease in ascular resistance , followed by a peripheral ascular receptor mediated increase in asoconstriction ( 1 , 4 ) 该作用被假设发生,通过对来自于中枢神经系统的交感系统的最初抑制,伴有相关的血管阻力的降低,并伴随着外周血管受体介导的血管收缩的增加[ 1 , 4 ] 。