What are the means of dealing with the pathogen that has burst into the body?

The main means of combating pathogens that are introduced into the human body are the organs of the immune system. The organs of the immune system are divided into central and peripheral. Peripheral organs include the tonsils, lymph nodes, spleen, appendix, accumulations of lymphoid tissue. These organs, the first to protect the human body, when pathogens enter it. To the central organs of the immune system: bone marrow and thymus. These organs are under the reliable protection of the bone tissue, and they produce lymphocyte cells, which fight against foreign substances (viruses, bacteria) by neutralizing them.