Innate immunity is not specific to any one pathogen but rather constitutes a first line of defense, which includes anatomic, physiologic, endocytic and phagocytic, and inflammatory barriers.

• 从进化上看，固有性免疫比特异性免疫出现的时间要早；固有性免疫具有识别和排斥的两个基本特性；固有性免疫也包括细胞免疫和体液免疫两种反应类型；