sympathicotonia

MB leads little changes of hemodynamics due to inhibit cardiac sympathicotonia and pneumogastric nerve simultaneity, but TEB brings the evident changes due to only inhibit pneumogastric nerve.

纵隔阻滞外阻滞相比，外阻滞抑制交感神经，引起明动力变化，而纵隔阻滞同时抑制心交感和心迷走神经，不引起明动力变化。