机体管腔内衬的黏膜具有许多保护机制使其免受外界环境的损害 ,这不仅包括非特异机制 ,即通过黏液、消化酶、胃酸保护黏膜表面 ,还包括免疫系统提供的特异性机制。黏膜内大量的淋巴细胞在免疫防御中起重要的作用。不同部位的黏膜内淋巴组织具有大致相同的形态 ,以相似的方式发 The lumens lining of the body has a number of protective mechanisms that protect it from the environment, including not only nonspecific mechanisms that protect the mucosal surface with mucus, digestive enzymes, and gastric acid, but also the specific mechanisms provided by the immune system. A large number of lymphocytes in the mucosa play an important role in immune defense. Mucosal lymphatic tissue in different parts has approximately the same morphology and is made in a similar way