机体受周围环境的影响、各种感染、抗原和变应原侵袭粘膜和皮肤。人类从首次到末次呼吸和吞咽,即从出生到死亡,不断地与外来抗原或变应性物质接触。因此,在我们生活期间识别这些“自身的”和“非自身的”物质极为重要。内环境稳定(homeostasis)是基于组织完善的防御机理,这种机理保护着机体,无论那些“非自身的”物质是否是传染性的。 The body affected by the surrounding environment, a variety of infections, antigens and allergens invasion of mucous membranes and skin. From first birth to last breath and swallowing, from birth to death, humans constantly come into contact with foreign antigens or allergic substances. Therefore, it is extremely important to recognize these “own” and “non-self” substances during our lives. Homeostasis is based on a well-organized defensive mechanism that protects the body, whether or not those “non-self” substances are contagious.