CBSE Class 9 Answered

It is in the lymph nodes where lymph collects and is filtered. Lymph nodes act as filters or traps for foreign particles and are important in the proper functioning of the immune system. The lymph fluid inside of the lymph nodes contains lymphocytes, a type of white blood cell, which are continuously recirculated through the lymph nodes and the bloodstream. In response to the antigens, the lymphocytes in the lymph node produce antibodies which go out of the lymph node into circulation, seek, and target the pathogen producing the antigen by targeting it for destruction by other cells and complement.