医 学专家称,人在冬天时,皮肤处在“收敛含　　　　　蓄”状态,血管收缩,减少散热,加强产热,以抵御寒冷。而到了春天,气温回升,人的皮肤不再为保暖而过多地工作,皮肤的血管和毛孔渐渐扩张,血液循环旺盛起来,供给大脑的血液相应减少,加上春天的温暖气温刺激和昼长夜短, Medical experts said that in winter, the skin is in a “convergent” state, vasoconstriction, reduce heat dissipation and enhance heat production, to resist the cold. In the spring, the temperature rises, the human skin is no longer as warm and too much work, the skin’s blood vessels and pores gradually expanded, blood circulation, a corresponding decrease in blood supply to the brain, coupled with the warmth of spring stimulation and day long night short,