“春眠不觉晓,处处闻啼鸟。”这是唐代诗人孟浩然的的著名诗句。这首诗形象地反映了人们在春人里的共同感受——困乏、想睡觉。春天,本是万物生长的季节,然而每到春天,不少人却昏昏欲睡,无精打采,这就是俗话说的“春睏”。那么,春眠又为何不觉晓呢?众所周知,人的生理活动是与外界有关联的,中医称之为“天人相应”。在冬天里,人受到寒冷的刺激,皮肤毛细血管处于“收敛”状态,血流量减少,汗腺、毛孔也相对闭合。皮肤就象一堵挡风墙,抵御着寒冷,减少热量散发,维持体温在37℃左右。由于体表血管收缩,使脏器血流量增大,大脑的血液供应和氧气供应也相对增加。这样,在漫长的冬季里,大脑逐渐养成了在高氧情况下工作的娇气。 “Spring sleep do not know dawn, smell the birds everywhere. ” This is the Tang Dynasty poet Meng Haoran’s famous verse. This poem vividly reflects people’s common feelings in the spring - sleepy, want to sleep. Spring, this is the season of growth of all things, but every spring, many people are drowsy, listlessness, which is the saying goes “spring sleepy.” So, why sleep do not feel it? As we all know, human physiology is related to the outside world, Chinese medicine called “God”. In winter, people are stimulated by the cold, the skin capillaries in the “convergence ” state, reduced blood flow, sweat glands, pores are relatively closed. The skin is like a wall of wind, to resist the cold, reduce heat dissipation, to maintain body temperature around 37 ℃. Due to surface vasoconstriction, so that organ blood flow increases, the brain’s blood supply and oxygen supply is also relatively increased. In this way, in the long winter, the brain gradually developed in the case of high oxygen stressfulness.