Acupuncture stimulation at the Waiguan of the right and left hands reduced the length of afferent and efferent loops, width of efferent loop and the width of loop peak;

• 针刺右手或左手外关都能减少甲襞微循环微血管之输入枝和输出枝长度，输出枝宽度和管绊顶宽，针刺作用持续至出针后10分钟。