a system (including the thymus and bone marrow and lymphoid tissues) that protects the body from foreign substances and pathogenic organisms by producing the immune response
The system that differentiates self from non-self and protects the body from foreign substances and pathogenic organisms by producing an immune response. It includes organs such as the thymus, the spleen and lymph nodes; tissue such as bone marrow, and lymphoid tissues such as the tonsils; cells such as lymphocytes including the B cells and T cells, and cell products such as antibodies.