人生来就有一道道天然的生理屏障。还是胎儿时,胎盘将母子相隔,使二者血液不相混合,并为胎儿提供氧气、营养及抗病因子,故称之为“胎盘屏障”。大脑是人体最重要的器官,除有坚硬的颅骨保护外,脑细胞周围有一层结构复杂的基膜,它可以阻止某些毒物、药物、微生物进入脑组织内,这就是“血脑屏障”。而皮肤、血液、淋巴、呼吸道纤毛、免疫系统等等,都是机体的 People have a natural physiological barrier. Or when the fetus, the placenta will be separated from the mother and child, so that the two blood are not mixed, and for the fetus to provide oxygen, nutrition and anti-factor, it is called “placental barrier.” The brain is the most important organ of the body. In addition to its hard skull protection, the brain cells are surrounded by a complex basement membrane that prevents certain toxicants, drugs and microbes from entering the brain. This is the “blood-brain barrier.” The skin, blood, lymph, respiratory cilia, the immune system, etc., are the body